Italy 🇮🇹, Calcata 

For 3 thousand years, people have used the flat surface of the volcanic rock as a safe haven from attack. A single road, blocked by gates, leads to the site surrounded by cliffs.

Since there was nowhere to expand horizontally, the construction went vertically, but not up, as is customary, but down. For thousands of years, the rock under the houses has been pitted with multi-tiered cellars. Eventually, in the 1930s, the government became worried that it would all collapse someday. New houses were built nearby on flatter places and people were forced to move there.

However, in the 1960s, artists began to move into houses abandoned in such a picturesque place, followed by hippies and just squatters looking for warmer places on Earth. The ban on settlement was canceled, completely odious characters were kicked out, and the rest were offered to formalize ownership of housing and assume obligations to maintain the cultural object in order.