Oct. 1, 2010  -- The main Hawaiian Islands all have nicknames. Oahu is the "Gathering Place." Maui is the "Valley Isle." Kauai is the "Garden Island."

But one island is hardly known at all, even by most state residents.

Niihau, about 18 miles northwest of Kauai, is the "Forbidden Island." It has been privately owned by the same family since 1864, when Elizabeth Sinclair purchased it from King Kamehameha V for $10,000.

"My great-grandmother purchased the island from the monarchy and it's been virtually unchanged since that date by my family," says Bruce Robinson, who owns the island with his brother, Keith. "We've tried to maintain the request of the King when it was turned over. We maintain the island for the people and continue to work it as he had."

The island is a pristine, critical habitat for highly endangered species, and one of the most-coveted travel destinations in the world.

Niihau (pronounced NEE-EE-HOW) actually became the "Forbidden Island" during a polio epidemic in the Hawaiian Islands in 1952.

"My uncle wanted to protect the residents here from the epidemic and it was forbidden to come out here unless you had a doctor's certificate, and there was a two-week quarantine," Robinson says. "And it worked. We never got polio out here."

The name stuck and, indeed, the only people allowed on Niihau for generations were relatives of the Robinsons and the 130 or so Native Niihuans living in the village of Puuwai. To this day, very few people ever get to visit the island. ABC was the first U.S. network allowed to film there.

"Yeah, there have been a lot of people over the years who tried to get out here and we have never allowed the merely curious to come over in the past," says Robinson, 69, who married a Native Niihauan and has seven children.

"We've had a lot of requests, including people who are about to die and they have to come over and see the last place on earth they haven't seen."

Not even rock stars get special treatment. Mick Jagger called recently requesting permission to land a couple of his helicopters on Niihau. Robinson said no. Royalty and the super-rich make the request and get the same answer.

As with the spectacular, imposing 1,200-foot cliffs that buttress the windward side of this 72-square-mile paradise, the family has stood firm.

But there is a way to visit Niihau.

Several years ago, the Robinsons started offering outsiders a rare glimpse of this extraordinary place, running helicopter tours from the western shore of Kauai. Visitors check in at the Niihau Helicopters office in the little town of Kaumakani, not far from the town of Waimea.

After a weigh-in and safety briefing, pilot Dana Rosendal flies them to Nanina Beach on the north shore of the island, then leaves them alone for three-and-a-half hours to explore, snorkel or just contemplate the extraordinary solitude that once was Hawaii.

"When we got our helicopter and opened the limited tours, yeah, that made our life easier," Robinson says with a laugh. "Now we just direct them over to the tour office. But it is a great tour, and it's worthwhile for someone to see it, if you can do it, because it takes you back in time in Hawaii, into something that you won't see anywhere else.

"When you come out to Niihau, what you are immediately going notice is the peace and quiet," he continues. "The fact that you're going out to a beach that doesn't have any people on it, doesn't have a lot of foot tracks on it. It's an open, empty beach."

One of the Greatest Shows on Earth?

Mike Faye, owner of Waimea Plantation Cottages, grew up on the western shore of Kauai, but like most Hawaiians only knows Niihau as a figure on the horizon. And yet Faye says it doesn't matter if Kauaians never actually step foot on the "Forbidden Island" in their lifetime; it's as much a part of their lives as the humpback whales that return to these waters each winter.

"Growing up as a kid, in the mornings the sun would reflect off the mountains there and it was almost like you could reach out and touch the place," says Faye, whose family has lived on Kauai and known the Robinson family since the mid-1800s.

"Niihau was always like a silent sentinel out there across the ocean, giving us some comfort from storms and the wide open ocean out beyond."

The sunsets off Kauai are considered one of the greatest shows on earth -- and in each performance, in a supporting role, her sister Niihau -- to Kamaaina, or locals, mysterious, yet benevolent.

"We're pretty much the western-most side of the day, so to speak," Faye says. "The International Date Line is right out there, it starts the day. The west ends and the east starts. To us, Niihau gives us that point on the horizon out there. It's close, it's always there. It guards us from that side of the world."

As the keepers of Niihau, the Robinsons have also worked hard to safeguard the island and its residents; a promise made by their great-grandmother to the King in 1864.

"When the King sold the island to the family," Bruce Robinson says, "he said to the family, 'These are now your subjects. You are to take care of them the best you can for the rest of time.' And our family has continued that.

"It's an island that's maintained the original Hawaiian lifestyle, the kahiki lifestyle, which is traditional, back to the 1800s and earlier, and it's still alive today and it's working. But it's under extreme pressure from the outside world, and we're trying to save it from that.

"The tours are solely for people to come see an unspoiled Hawaiian Island," Robinson continues. "We will not take them to the village or put the residents into a fishbowl-type of situation. We don't even fly over the village. That is not what we're about. We respect their privacy, we respect their desire to live untouched by the outside world and we intend to preserve that."

Robinson is also a noted conservationist, preserving and documenting many of Niihau's natural plant resources. The island is designated as a critical habitat for endangered and endemic species such as the endangered Olulu plant and the Pritchardia palm tree, named for his Uncle Aylmer.

But perhaps the best-known endangered species on Nihau is the Hawaiian monk seal, llio-holo-i-ka-uaua to Hawaiians, or "dog that runs in rough water." It is considered the most endangered of all the world's seals, with only about 150 left in the main Hawaiian Islands; by last count, 87 of those on Niihau alone. The island is more than just critical habitat for the population. It is the primary nursery.

"There's a huge number of seals there," says Charles Littnan, lead monk seal scientist for National Marine Fisheries Service, of the National Oceanic and Atmospheric Administration. "It's probably the seals at Niihau that have recolonized the rest of the main Hawaiian Islands. It's nice to know that they have that place of refuge."

Today, it's tough to visit the beaches of Kauai without coming across a monk seal resting on a beach, protected by yellow ropes and a "DO NOT DISTURB" signs. People throughout the state have joined together to give these extraordinary creatures space. But Native Hawaiians haven't always had a great relationship with the monk seals.

"When they move into an area, they're voracious eaters," Faye says. "They're going to wipe out a lot of the fish. So, we've had to learn how to adapt and live together, as we have with other animal species who come here to the Islands. Including humans."

Attempting to Save Monk Seals

Robinson says, "The natives knew that the seals took so much food that they felt it endangered their existence, so they killed all the seals. So what we're doing now is working with the federal government, helping with the seal count, and seeing what we can do to save them."

Robinson took the ABC crew on a personal tour of the areas the family has set aside for the seals. He says the video captured that day was the only known footage of Niihau monk seals nursing. He led the crew to at least a dozen mothers with newborn pups, presenting them like a proud -- and protective -- father.

"We've done a lot of monk seal preservation here," he explains. "It started really by accident when the first monk seal showed up on a beach here in the '70s. We realized that this is the last mammal on earth that swam with the dinosaurs and we do need to preserve this thing."

Although the Robinsons haven't always seen eye-to-eye with state and federal governments, Bruce has recently reached out to NOAA Fisheries to find ways to work together to save the monk seals. He's initiated the first-ever survey of the local population, a critical start in any conservation effort.

To date, scientists have known very little about the monk seals of Niihau. Getting access to the population here is a boon for the agency. And now that "Forbidden Island" is beginning to open up to outsiders, more people are getting a chance to see these creatures in their pristine habitat, adding to an already-growing constituency for their protection.

The idea to do half-day tours came when the Robinsons realized that a medevac helicopter was needed for the population there.

"The limited tourism that we're doing now is good in that it helps to defray that cost," Robinson says. "But the real benefit to us is that it's low-impact. We like the low-impact tourism. We don't want to do high-impact tourism like Waikiki and all the hotels because that would destroy what is here."

Still, any place called "Forbidden" is fertile ground for rumors. And Robinson says he's heard them all.

"There are stories that have been generated of captives living out here, people who can't get out to the cities. That is totally false," he says. "They go back and forth all the time. In fact, every person on Niihau has been to the mainland. They know all about it. It's a well-traveled population. Totally bilingual, some working on three languages. While it is an ancient type of culture, they're a very modern type of people."

They're also the green type.

"Every house has solar power," he says. "Every house has its own water system. At the time when we had hurricanes, where the rest of the islands took months to recover, Niihau took three days and we were back on our feet, the schools were running and everything."

While the ABC crew was there, the helicopter returned from Kauai filled with villagers and various sundries from town. The kids pouring out of the aircraft rushed over to Robinson, with two smaller ones hugging each leg. He's clearly much-loved here. The villagers -- and Robinson -- spoke to each other in a flowing, joyful Native Hawaiian dialect not heard anywhere else in the world.

Robinson's ranch manager and another young Niihauan were introduced to the crew, and then all joined in a bumpy ride in Robinson's doorless, roofless, windshield-less, red-dirt-encrusted truck -- one of the few vehicles on the island -- to go see the seals.

Robinson's hope for the future includes continuing limited, low-impact tourism as a means of supporting the economy of Niihau, and to continue a working relationship with the U.S. Navy that began in 1924 and now provides about 80 percent of the island's income. Niihau currently hosts a missile-defense installation operated by the Navy's Pacific Missile Range Facility based on Kauai's western shore.

A Commitment That Will Never Die

Robinson also has visions for wind power development there: Niihau sits crossways to the trade winds, an ideal spot.

"It would be a great thing for this island, except that we can't transport that power anywhere, so that becomes a problem," Robinson explains. "But there's still the problem of transporting that power. But there's going to be great strides made in the near future in transoceanic cables for electricity and at that point it may become viable."

The future of Niihau is a remarkably prescient subject for Robinson, interesting for someone with such a singular connection to the past. He and his brother still carry the paperwork from the agreement their family struck with King Kamehameha V almost a century-and-a-half ago and are quick to share it with others.

To them, it is a binding, living, evolving document, a commitment that will certainly outlive them but never die.

For all the broken promises Americans made to the monarchy that they would ultimately and illegally overthrow in 1893 -- which, incidentally, the Robinsons point out that the family opposed -- at least this one was kept.

"A person doesn't own land as such," Robinson says. "It's on loan from God and you have to maintain it as best you can."

To learn more about Niihau, check out the following websites.

Niihau Helicopters

Waimea Plantation Cottages

Kauai Visitors Bureau