Ancient City of Sigiriya, Sri Lanka

Sigiriya (Lion Rock) is famous for its palace ruins on top of a massive 200 meter high rock surrounded by the remains of an extensive network of gardens, reservoirs and other structures. The rock itself is a lava plug left over from an ancient long extinct volcano."

(Quote from wikitravel.com). The complex around the rock and on the summit was built in the 5th century, to serve as a capital, but soon after that Anuradhapura was restored as Sri Lanka's capital and Sigiriya was used as Buddhist monastery until the 14th century. Sigiriya is inscribed as UNESCO World Heritage site, it is the most visited place in Sri Lanka.