One of the great centres of Eastern Orthodox monasticism is Mount Athos in Greece, which, like Vatican City, is self-governing. It is located on an isolated peninsula approximately 20 miles (32 km) long and 5 miles (8.0 km) wide, and is administered by the heads of the 20 monasteries. Today the population of the Holy Mountain is around 2,200 men only and can only be visited by men with special permission granted by both the Greek government and the government of the Holy Mountain itself.