Bosra

Bosra is an ancient ruined city in southwestern Syria near the Jordanian border, designated a UNESCO World Heritage Site in 1980. Once the capital of the Roman province of Arabia Petraea, it holds one of the world's best-preserved Roman theatres — a 2nd-century structure built entirely of black basalt with a capacity of up to 15,000 spectators. The city's layered history spans Nabataean, Roman, Byzantine and early Islamic eras: a 4th-century cathedral considered a prototype for later Byzantine centrally-planned churches stands close to the Omari Mosque, regarded as one of the oldest mosques in the Islamic world. Medieval Arab military engineers encased the Roman theatre within a fortress, turning it into a citadel — an architectural palimpsest that condenses two millennia of history into a single monument.