Yaha is Ethiopia’s earliest known capital, as the birthplace of the country’s earliest high civilization; it is well worth visiting nowadays. The ruins of this large, pre-Christian temple, erected around the fifth century BC, consist of a single roofless oblong chamber 20 meters (66 feet) long by 15 meters (50 feet) wide. The windowless 10 meters high walls are built of smoothly polished stones, some of them more than 3 meters long, carefully placed one atop the other without the use of mortar.