Ustra

Ustra ( _bg. Устра) is a castle in the eastern Rhodope mountains, southern Bulgaria. Its ruins lie at 4 km to south of the Ustren village situated on a hill at 1,015 meters above the sea level.

The fortress was built in the 10th century to protect an important trade route. Its was taken by the armies of Simeon the Great (893-927) but after his death it was among the lands given back to Byzantium in return for the recognition of the Imperial title of the Bulgarian rulers. Between 12th and 14th century it frequently changed hands between the two Empires but the Byzantines held during most of the time.

The ruins are located at 1,5 km from the road between Ustren and Zlatograd. There is a hut of the same name nearby. The preserved height of the walls reaches 10 meter.

Honour

Ustra Peak on Livingston Island in the South Shetland Islands, Antarctica is named after the fortress of Ustra.