2. PETRA (JORDAN)

Key point of passage of the Silk Road, it was built in the Nabateao kingdom. After its abandonment it was discovered in 1812 by the Swiss explorer Johann Ludwig Burckhardt.

It is made up of 1,500 meters in length, dated 312 B.C. Petra was named by Smithsonian Magazine as one of "28 Places to See Before You Die".