On a small, rocky peninsula jutting out into the Aegean Sea is Mount Athos, home to 20 of the world's most ancient and remote monasteries. Today, the mountain is an "Autonomous Monastic State" of Greece, but it's really more like an independent country run by the Eastern Orthodox Church. Visitors must cross border controls to enter from Greece (by boat—there's no road over the mountain), and the country's Ministry of Foreign Affairs administers the peninsula. It's as close as you can get to a Christian Tibet.
Some hella cool architecture too, but this is crazy:
https://chanc.ee/20210810-autonomous-monastic-state.htmlMount Athos is hard to get into for men, but downright impossible for women. The monks banned women in the 11th century, even going so far as to ship out all the female animals. (Their one concession to equal rights: letting female songbirds and insects stick around.) No woman has legally set foot across the border in over a thousand years.