This is part of CNET's Road Trip 2017 summer series "The Smartest Stuff," about how innovators are thinking up new ways to make you — and the world around you — smarter.

At one time, the only way to get from Kintobo to the hospital was by foot. The small village lies 7,700 feet up a steep, green mountain in Rwanda's remote Western Province.

People suffering from tropical illnesses like malaria, dengue fever and tuberculosis trekked two hours down the mountain slope to reach the closest doctors. Parents toted sick children on their backs using wide sashes cinched around their waists. And anyone seriously hurt or in labor had to be carried in a hammock tied to two logs — shouldered by two people in front, two in back — as the person inside swayed back and forth with each step along the mountain's muddy trails.

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"Imagine how this population was suffering trying to go down to the health facilities," says Bertin Gakombe, a lanky Rwandan with a toothy smile, who's program manager for the nonprofit organization Health Builders. "It wasn't easy."

In rural Rwanda, people don't measure distance in miles or kilometers. They measure it by how long it takes to walk somewhere.

Four years later, the people of Kintobo no longer need to walk down the mountain to get medical care. A state-of-the-art health center now serves Kintobo's more than 17,000 residents. Its clean, modern design is laid out for easy navigation. Patients arrive at the check-in counter, circle through to a waiting area and then pass along to consultation rooms.

A young girl waits at the Kintobo health center. James Martin/CNET

We're in Kintobo on an overcast day in July while two dozen people wait to be seen. Babies cry, people cough. A small girl in a green dress sits quietly on a wooden bench, eyes wide, legs dangling. In a separate hospitalization area that can accommodate people for more than 72 hours, a teenage boy is wrapped in a blanket, sleeping. A mosquito net hangs above his head. In the maternity ward, a young woman in labor sits on the floor moaning.

"Struggling much has taught us how to speed up our thinking and development in order to recover from the past," Gakombe says. Health Builders — which designs heath management systems, constructs medical facilities and installs small-scale solar systems — built the center at the Rwandan government's request.

Rwanda is known for the 100 days of genocide that saw an estimated 800,000 people slaughtered, forced 2 million more to flee and left the East African country in shambles. That was in 1994. Today that past is mostly a painful memory.

Modern-day Rwanda is a bustling nation that's safe, clean and efficient. Its government wants the country to be the Singapore of Africa — a leader in business, commerce and technology. The World Economic Forum last year called it one of the fastest-growing economies. That's saying something considering it's a landlocked nation the size of Maryland, without natural resources.

But Rwanda also remains one of the world's poorest countries. It struggles with an overworked electrical grid, intermittent running water and few paved roads outside its capital, Kigali. Rwandan President Paul Kagame has been both praised for bringing economic stability to the shattered country and accused of running an authoritarian dictatorship that crushes opposition and dissent. It's a topic the people here just don't talk about.

We came to this land of contradictions after experts pointed to it as an unlikely leader in health care. A constitutional amendment in 2003 listed health as a human right. The country has universal coverage. Malaria, tuberculosis, HIV and maternal and child mortality have plummeted. And Rwanda has opened more than 50 health facilities in the past 15 years, part of a policy to provide health care within an hour's walk, for everyone.

To achieve its aims, Rwanda has been trying new things. It's given airspace to a Silicon Valley drone company that flies blood to hospitals in minutes. It's worked with European startups and investors to help bring electricity to rural areas and the health clinics that serve them. And it's inaugurated one of the first cancer centers in the region.

"When you're in a conflict zone, you only have one way to go afterwards," says Tyler Nelson, executive director of Health Builders. "Rwanda had the scenario where they were rebuilding from zero. It was almost like the country came together and, with one voice, they rebuilt almost like a clean slate."

A rush of blood

Every day in a rocky field in Muhanga, about an hour west of Kigali, a group of young kids press their noses against a chain-link fence with barbed wire running across the top. They're here to see something that's become an ordinary occurrence in the last few months.

The kids gather to watch drones take off from launch pads that look like they're built out of K'nex blocks. But these aren't garden-variety quadcopter drones. They look like 6-foot-long, twin-engine planes, and they're launched with the flair of rockets. One of the flight operators, wearing safety goggles and speaking into a walkie-talkie, pecks at an iPad as he prepares for takeoff. When he's given clearance, the drone slingshots into the sky.

A few yards away, a man watches from a makeshift air traffic control deck built atop an old bathroom.

A Zipline employee prepares a drone for takeoff. It'll be flung from its launchpad to deliver blood to a hospital. James Martin/CNET

This happens at least five, and sometimes up to 20, times a day.

We're at the compound of a company called Zipline that's headquartered in Half Moon Bay, California, about a half hour's drive from Silicon Valley. Zipline is also backed by some of the Valley's heaviest hitters, including venture capitalists Andreessen Horowitz, Sequoia Capital, GV (formerly known as Google Ventures), Yahoo co-founder Jerry Yang, and Paul Allen, who co-founded Microsoft.

Right now Zipline operates only in Rwanda.

The drones carry a unique type of cargo: blood, platelets and plasma. Weighing about 30 pounds each and carrying roughly 3 pounds of blood, the drones fly to nine hospitals throughout the western side of the country after receiving orders via WhatsApp texts. Their goal is to deliver blood to these medical centers in fewer than 20 minutes, instead of the up to three hours it can take by road.

The drones don't land at the hospitals. Instead, the packages drop to the ground by parachute, and the drones simply circle back to the compound.

"We approached different governments," says Maggie Jim, Zipline's chief of staff. "Rwanda was like, let's do it.

"Rwanda has a special appetite for entrepreneurship," she adds.

Starting next year, Zipline will also begin operations in Tanzania, eventually making up to 2,000 deliveries a day to more than 1,000 health facilities across that country. But the company wants to do more than just deliver blood or medical supplies. It aims to become a drone delivery system for everything, much like Amazon and Google.

Not everyone is a fan.

Critics say blood delivery by drone is a high-end solution for a low-cost problem and that money could be better used to train more doctors. They also say the idea of using drones in a country as small as Rwanda, where all hospitals are within a three-hour drive, seems unnecessary.

Blood, platelets and plasma are kept chilled at Zipline's compound, ready to be delivered in under 20 minutes to one of nine hospitals in the western part of Rwanda. James Martin/CNET

As we tour the grounds, one of the drones makes its way back, flying in at more than 60 miles an hour. We watch as a hook on the drone's underside snags a giant rope strung between two poles. The drone stops instantly — much the way fighter jets land on aircraft carriers — then falls onto a big, inflatable mat.

The kids watch at the fence but don't bat an eye. "It used to be that the whole fence was filled," says Jim, looking at the kids. "Now it's like, eh, drones."

Take us to a place where there is nothing

A young boy no more than 6 years old sits in the sun outside the massive, 65,000-square-foot Butaro Hospital compound in rural northern Rwanda. He happily jumps up when he sees the hospital's oncology director, Dr. Cyprien Shyirambere, who uses his notebook to sweetly tap the boy's bald head.

"He just finished 30 months of treatment," Dr. Shyirambere tells us.

The boy was diagnosed with acute lymphoblastic leukemia about three years ago. Rare in adults, it's one of the more common childhood cancers, and this boy had spent at least a third of his life in chemotherapy. "Now he's in remission," says Dr. Shyirambere, a slim man who carries an air of calm about him.

Where once there was nothing: Butaro Hospital now serves as an example that other hospitals and health clinics in Rwanda can replicate. James Martin/CNET

The boy's diagnosis would've been a death sentence before Butaro's Cancer Center of Excellence opened in 2012. It's the first public cancer treatment center in Rwanda and one of only a handful in east Africa. Before it opened, Dr. Shyirambere, a pediatrician by training, had to turn away children with cancer who came to see him.

"How do we start a cancer center where there are no oncologists, no cancer drugs, but there are patients?" says Dr. Shyirambere. "Is it just to let people die?"

Every Thursday, Dr. Shyirambere holds a conference call to discuss difficult cases with a team of oncologists from hospitals in the US, including Dana-Farber Cancer Institute and Brigham and Women's Hospital, which also mentored and trained his Rwandan staff. Initially, Butaro had to send biopsies to Brigham and Women's Hospital for diagnosis, but now most things can be done in-house. Since it began operations, the cancer center has treated more than 6,000 patients.

Butaro Hospital was built and is operated by Partners in Health, a nonprofit health care organization based in Boston. The group, which has been working in Rwanda since 2005, asked the government in 2007 if there were other districts that could use its help.

"Take us to a place where there is nothing," Dr. Shyirambere says Partners in Health told the government. "They took us here."

There was nothing in Butaro. No roads, no electricity and no hospital. There were, however, 350,000 people living with minimal access to basic health services. Butaro today is completely transformed. The government is building the first paved road in the region and the local town now has shops, taxis, a gas station, an ATM and even high-speed internet.

Across the hill from the hospital, we see a new medical school being built: the University of Global Health Equity, or UGHE — another brainchild of Partners in Health. Funded by the Bill and Melinda Gates Foundation and the Cummings Foundation, the med school will teach rural health care in a rural setting.

A woman and child in Kintobo's new health center. James Martin/CNET

"Teaching hospitals cannot approximate the experience of being in the field," says Dr. Paul Farmer, co-founder of Partners in Health, who has become a cult figure in the world of medicine for his humanitarian work in developing countries. "The classroom is not only a clinic, but also a home visit, a case study and more."

Construction for the university is buzzing on the 250-acre parcel, which was donated by the Rwandan government. As a cement mixer whirs and tractors drive back and forth, workers in blue jumpsuits haul concrete blocks in wheelbarrows and manually bend rebar. Emmanuel Kamanzi, director of campus development for UGHE, points to a cluster of structures being built below us, and says they will house students and professors. All rooms will have views of Rwanda's high-peaked Virunga mountain range.

"Think of young children dying of pneumonia in a rural area. Treating pneumonia in a hospital is one of the easiest things you can do. We want our students to have that exposure," Kamanzi says. "The country itself is a case study in showing medical students how change can happen."

He says the university's first group of medical students is slated to start in September 2018.

Butaro has become the de facto centerpiece for Rwanda's advancements in health care. It's also an example others can replicate, such as the new cancer center the government expects to open this month in Kigali, says Dr. Egide Mpanumusingo, clinical director for the district where Butaro Hospital is located.

"Butaro has shown Rwanda cancer treatment is possible," Dr. Mpanumusingo tells us. "In five years, you come back, you will see many changes. And that's not just Butaro, it's the whole country."

Umuganda

Rwanda is an endless expanse of steep, jade-green mountains. It's known as the land of a thousand hills. From a distance, its lush terraced farms — filled with cabbage, corn and potatoes — look like patchwork quilts of green, brown, blue and yellow. Alongside the mountains' windy roads, people carry jugs of water and long stalks of sugarcane on their heads. Kids run by with goats and sheep on leashes.

Called the "land of a thousand hills," Rwanda is a beautiful country of mountains, volcanoes and terraced farms. James Martin/CNET

The country is orderly and immaculate. Not only are plastic bags illegal, there's no litter anywhere. That's because of monthly Umuganda day, which means "coming together" in the local language, Kinyarwanda. On Umuganda, every Rwandan must go out and clean the streets and countryside.

In Kigali, motorcyclists zoom by on newly paved streets driving the speed limit and wearing helmets — it's the law. The country has car-free days every first Sunday. You don't see homeless people or beggars. And it's safe. You won't get robbed, assaulted or even hustled.

Some might call Rwanda a model society. Others say it's an oppressive dictatorship under President Kagame, who was re-elected for a third, seven-year term last month with nearly 99 percent of the vote. A constitutional amendment passed in 2015 allows him to serve until 2034. When thinking about Rwanda's president, the phrase "he made the trains run on time" often comes to mind.

It was Kagame and the Rwandan Patriotic Army he led that ended the genocide in 1994 by taking control of the capital.

It's hard for anyone to fathom what happened that year. For more than a century, the country had been divided between two castes, the Hutus and the Tutsis. The animosity boiled over in 1994. In 100 days, Hutu extremists armed with clubs and machetes spread across the hills and massacred nearly a million Tutsis and moderate Hutus with the aim of complete annihilation. No one was safe. Children, the elderly and pregnant women were brutally executed.

Churches were burned, schools were ransacked and hospitals were left in ruins. Entire villages disappeared. Skulls littered the streets and, gruesomely, dogs were seen running around with human bones.

"A lot of bad aspects of Rwanda, like being authoritarian, are true," says Benjamin Chemouni, a Rwanda expert and lecturer at the London School of Economics. "That may be problematic in the long run, but it's allowed the government to rebuild a state after a horrible traumatic experience."

The shape of Africa

Twaha Twagirimana keeps the Rwamagana Solar Power Station up and running. It's a full-time job — with the occasional 11 p.m. call telling him the solar grid is down and he needs to get out of bed to go to the solar plant.

The disruptions are called "grid trips," and if there's a system failure that lasts more than half an hour, he has to manually restore it before sunrise. "It's irritating when you're sleeping," says Twagirimana, wearing a hard hat, fluorescent yellow safety vest and work boots.

He's the plant supervisor at the massive, 8.5-megawatt solar power plant. It's a vast, unusually flat space, past roads lined with banana trees. When the solar farm began operations in 2015, it was the largest in east Africa. A bigger one in Uganda now holds that distinction.

Today, about 71 percent of Rwandans live in rural, mountainous regions, areas where electricity is practically nonexistent. In its way, the Rwamagana Solar Power Station paints a vivid portrait of how everything is connected as Rwanda rebuilds itself: health care, infrastructure, policy.

A worker at the Rwamagana Solar Power Station rides through the plant with jugs of water. James Martin/CNET

We're here on a sunny, hot day, which, contrary to what one might think, isn't optimal for harvesting the sun's power. Yes, sunny is good, but cooler temperatures are ideal for the more than 28,000 panels spread out before us. When viewed from above, the panels form the shape of the African continent.

"We're going to South Africa now," Twagirimana jokes as we walk down through the field. The power station rests on 42 acres of bush, full of prickly plants and — though Twagirimana tries to downplay it — venomous snakes. Red dirt roads slash through the rows of panels. Nearby, a group of men in hard hats and blue jumpsuits spray and dry the panels with a hose and long mops.

Built with help and funding from Amsterdam-based Gigawatt Global; renewals investor Scatec,based in Oslo; and the Norwegian government's Norfund, the Rwamagana solar farm generates 5 percent of Rwanda's electricity. And it's growing.

The facility, for example, is building another, smaller solar plant to serve the local Rubona Health Center. By December, the health center will be one of only a few in the country to run on solar energy.

Fiber optic trees

Rwanda means "the universe" in Kinyarwanda. It's the source of Africa's three major rivers, and both continental divides meet here. Its steep chain of volcanoes to the north makes it isolated, impenetrable. It seems like a place of both the impossible and all-possible.

As our car careens up toward those volcanoes, the dirt road becomes a dark russet red. Children wave and yell "muzungo," foreigner, as we pass by. The drive is bumpy. It used to take five hours to get to Kintobo or Butaro from Kigali. But after the health facilities were built, the government began to fix the roads, and travel time was cut in half. It'll soon be even faster to get to Butaro, because the government is paving the road.

"This is going to be the first paved road ever in the history of this district," UGHE's Kamanzi tells us.

Out our window, we're surprised to see miles and miles of fiber optic cables hanging from trees. They almost look like power lines. The cables, which enable high-speed internet, have accumulated a light layer of red dust from the cars passing by. Oftentimes, fiber cables go under existing roads. It's a long and expensive process to upend the infrastructure. But in this case, the cables will be put underground as the roads are paved. Up at Butaro, doctors rely on those fiber cables for communication with the outside world.

Inside the courtyard of the hospital, there's a towering tree with a thick gnarled trunk and expansive leafy canopy. It's an Umuvumu, or Kingdom Tree. It got its name because this type of tree traditionally stood at the gate of the king's palace.

According to Rwandan legend, the trees have the power to protect, cultivate reconciliation and cure sickness. People used to gather around the trees for healing.

"People around here still believe in this tradition — that tree," Dr. Shyirambere says. "People would come for hundreds of years to get healed from diseases." Not anymore.

"Now they come to see the doctors."

Photography by CNET Senior Photographer James Martin. This article originally appeared on CNET.