6Petra, Jordan

Carved directly into rose-red cliffs, Petra is an ancient city that served as the capital of the Nabataean Kingdom. 

Established as early as 312 BC, Petra is famous for its rock-cut architecture and water conduit system. The most iconic structure, Al-Khazneh (The Treasury), is a stunning example of Hellenistic architecture. Walking through the Siq, a narrow gorge that leads to Petra, and seeing the Treasury for the first time is a breathtaking experience.