Mount Athos (not in the US but often referenced)

Mount Athos is an autonomous monastic community located on a peninsula in northern Greece, renowned for its rich Orthodox Christian tradition. It comprises 20 monasteries and numerous smaller monasteries and hermitages, primarily inhabited by monks dedicated to religious practices and contemplation. Accessible only to men and governed by a special administrative system, Mount Athos has a unique spiritual and cultural heritage, with monasteries preserving centuries-old religious art, manuscripts, and traditions. It is often called the "Holy Mountain" and serves as a significant center for Eastern Orthodox spirituality, pilgrimage, and monastic life.