Vardzia

Less a building on a cliff than a whole monastery cut into one. Vardzia was carved into a rock face above the Mtkvari river in southern Georgia between 1156 and 1203 and served as a royal monastery under Queen Tamar, whose name it is tied to. Today the cliff is honeycombed with exposed rooms, tunnels, churches and cellars, so you walk through it rather than just look at it. The highlight is the Church of the Dormition at the heart of the complex, still covered in its medieval wall paintings. Expect a lot of stairs and narrow tunnels, so wear closed shoes. It is a long day trip from Tbilisi, four hours or more each way by road, which is why many visitors pair it with a night nearby.