Petra, also called the “Rose City,” was carved out of rosy rocks in the Jabal Al-Madbah basin thousands of years ago. Known as the oldest city in the world, records suggest it was constructed as early as the 2nd century B.C., by the Nabataeans, and later fell into the hands of the Roman Empire. A UNESCO heritage site, the city is huge, spanning 102 square miles. Though visiting it on foot can be daunting, a virtual guide has been curated that takes you step by step through its most important landmarks, among them the Siq river, tombs, temple ruins, an enormous monastery, and Al Khaznah, the building whose detailed facade is carved out of a gorge wall. —E.C.