Petra:

By: Emil G. Hirsch , Louis H. Gray

Capital of Edom in northern Arabia, lying in a rocky valley surrounded by mountains, of which the highest is Mount Hor. The name is apparently a Greek translation of the original Hebrew designation of the place, "Sela" (= "rock"; II Kings xiv. 7; Isa. xvi. 1). Petra was captured by Amaziah, who changed its name to "Joktheel," although Isaiah ( l.c. ) still termed the city "Sela." In the third or second century B.C. it was conquered by the Nabatæans, whose chief city it became; and after the Roman conquest Trajan made it the capital of the province of Arabia Petræa, the town thus lending its name to the district. Petra declined after the fourth or fifth century C.E. , and was finally destroyed during the Mohammedan conquest.

Early in the nineteenth century the site of Petra was explored by Seetzen and Burckhardt, who made known its interesting ruins, chiefly Greek in architecture and consisting of temples, tombs, and an amphitheater.