Greece: Ancient Tiryns
While this ancient fortress looks like a bunch of boulders in disarray, it is in fact one of the oldest fortresses in the world with documented history spanning 7-8 thousand years from the Bronze Age! The height of the settlement was reached during the Mycenae civilization around the 1200 BC. The walls and structures and tunnels are made with massive boulders, which is known as Cyclopean architecture (since only mythical Cyclopes could take this apart and break it). Tiryns is also the supposed birthplace of Hercules and the place were he performed his 12 tasks. For two thousand years it lay completely abandoned and only relatively recent excavations uncovered the fortress.