The elder Jedi master Luke Skywalker retired to a life of solitude on a remote island on the planet Ahch-To. Or he ran away and hid there, if you want to be brutally honest. The beautiful island scenes in The Last Jedi were filmed on Ireland's Skellig Michael, which really has existing ancient stone huts.
The ancient Jedi shelter where Luke Skywalker resides is a very terrestrial building type called a clochán, a primitive stone dwelling that can still be found on Skellig Michael. These structures, also called beehive huts, were built by the ascetic Christian monks who first settled the island in the 6th or 7th century. Although beehive huts can be found across Europe and particularly western Ireland, the examples on Skellig Michael are probably the most striking and isolated in the world.
Skellig Michael is now a UNESCO World Heritage Site. While The Last Jedi was filmed on location there, they did not use the island's ancient clocháns. Reproductions were built for the movie. Atlas Obscura looks closer at these stone domes and how they were built in a place where there was no wood or mortar, hundreds of years ago.
(Image credit: Jibi44)