The pilgrimage to Makkah (hajj) is one of the required "pillars" of Islam for those who can afford the journey, and a once-in-a-lifetime experience for many Muslims. The responsibility for organizing this massive gathering, which occurs annually over an eight-day period between late August and early November, falls on the government of Saudi Arabia. The government hosts over 2 million people in one ancient city. This is a huge logistical undertaking, and the Saudi government has dedicated an entire government ministry to provide for the pilgrims and ensure their safety. As of the 2017 pilgrimage season, here are some of the statistics.

2 Million Total Pilgrims Issam Madkouk / Getty Images The number of pilgrims arriving from other lands has multiplied exponentially in recent years, from as few as 24,000 in 1941. However, in 2013, restrictions were put in place that limited the number of pilgrims entering Saudi Arabia due to ongoing construction at the holy sites and concerns about the potential spread of Middle East respiratory syndrome. Since then, the numbers have rebounded markedly. International pilgrims work with local agents in their home countries to arrange for travel. Pilgrims now mainly arrive by air, although several thousand arrive by land or sea each year.

600,000 Local Pilgrims Abid Katib/Getty Images From within the Kingdom of Saudi Arabia, Muslims must apply for a permit to perform ​hajj, which is only granted once every five years due to space limitations. In 2013, local officials turned away over 30,000 pilgrims who tried to enter the pilgrimage areas without a permit.

Dozens of Countries Photo by Muhannad Fala'ah/Getty Images Pilgrims come from around the world, of all ages, with varying levels of education, material resources, and health needs. Saudi officials interact with pilgrims who speak dozens of different languages. The "Daily Post" noted the statistics on the home countries of just some of the pilgrims: 184,000 from Pakistan

170,000 from India

127,000 from Bangladesh

90,000 from Turkey

41,200 from Malaysia

23,500 from Russia

12,700 from China

6,000 from the Philippines

3,500 from South Africa

14 Million Liters of Zamzam Water Abid Katib/Getty Images Officials distributed 14 million liters (3.7 million gallons) of mineral water from Zamzam, a well in Mecca which provides natural spring water to the millions of Muslim pilgrims who visit each year, notes "Arab News." Zamzam water is distributed by the cup in the pilgrimage areas, in small and medium-sized water bottles, as well as in larger 20-liter containers for pilgrims to carry home with them—or about 3 million water bottles total.

45,000 Tents Abid Katib / Getty Images Mina, about 3 miles outside Makkah, is known as the hajj tent city. The tents house pilgrims for a few days of the pilgrimage; at other times of the year it lays bare and abandoned. The tents are neatly arranged in rows and grouped into areas labeled with numbers and colors according to nationality. Pilgrims each have badges with their assigned number and color to help find the way back if they get lost. To prevent fires, the tents are constructed of fiberglass coated with nonstick coating and are fitted with sprinklers and fire extinguishers. The tents are air-conditioned and carpeted, with a hall of 12 bathroom stalls for every 100 pilgrims.

16,280 Officers Abid Katib / Getty Images Civil defense and emergency personnel are visible throughout the pilgrimage sites. Their job is to direct the flow of pilgrims, assure their safety, and assist those who are lost or in need of medical assistance. In addition to more than 16,000 officers, there were many other support personnel at the 2017 hajj, Cision PR Wire notes, including: 51,700 staff members representing more than 20 governmental entities working around the clock

6,300 staff members from the General Presidency for the Affairs of the Grand Mosque and the Prophet's Mosque providing cold Zamzam water for pilgrims at prayer sites

4,480 staff members providing municipal services for pilgrims, citizens, and residents in Makkah and the Holy sites

4,470 staff members from the General Department of Passports to prepare and equip the entry ports to receive pilgrims

3,706 scouts providing a wide range of services such as directions to lost pilgrims

100 Ambulances Muhannad Fala'ah / Getty Images Pilgrim health needs are met at 150 permanent and seasonal health facilities throughout the holy sites, with over 5,000 hospital beds, staffed by over 22,000 doctors, paramedics, nurses, and administrative personnel. Emergency patients are immediately cared for and transported, if needed, by ambulance to one of several nearby hospitals. The Ministry of Health stores 16,000 units of blood to treat patients.

6,000 Security Cameras Salah Malkawi / Getty Images The security and control command center for Hajj installed nearly 6,000 digital cameras to monitor the movement of pilgrims at the holy sites to ensure their safety at the 2017 hajj, said "Arab News." The high-tech command center for hajj security monitors security cameras throughout the holy sites, including 1,200 at the Grand Mosque itself.

1,500 Pounds of Silk Getty Images Silk, along with 120 kilograms of silver and gold thread, are used to make the black covering of the Ka'aba, called the Kiswa. The Kiswa is handmade in a Makkah factory by 240 workers, at a cost of 22 million SAR ($5.87 million) each year. It is replaced annually during the Hajj pilgrimage; the retired Kiswa is cut into pieces to be given as gifts to guests, dignitaries, and museums.