South Wall, Azraq, Jordan
Azraq's major claim to fame seems to be that T. E. Lawrence spent a rain-soaked and very uncomfortable winter here in 1917 (photo, interior). Located 90km east of Jordan in what was once a large oasis, the Roman fort was built in the 3d century and rebuilt under the Ayyubids in 1237. Its three-ton basalt doors (photo) were reported by Lawrence to shake the entire wall when slammed shut. The gate forms a right angle with the south wall for security; a machicolation and several arrow slits guard it from above.