Haller Bastion in Sibiu is a spade-shaped bastion built for defensive purposes in the second half of the 16th century. Part of the city’s late medieval fortifications, the bastion was situated in the south-eastern end of Sibiu’s defence rings.

It was erected at the initiative of the Italian general Giovanni Battista Castaldo and the mayor Peter Haller, who also gave it his name. The general was leading the Austrian troops that invaded Transylvania in 1551 and occupied it for 5 years. He was the one who thought of a system for reinforcing the citadel’s defence and hired the Italian architect Alessandro Clippa to design the project of the new fortifications. The project included 5 bastions placed at the corners of the defence ring, with large spaces for storing ammunition and housing troops in the lower part and with wide open spaces for placing the cannons in the superior part. However, various reasons determined the Austrian army to retreat in 1556, when only two bastions, including Haller Bastions, had been finished. The bastion had brick walls filled with earth, 223m long and 9m high, which were supposed to resist to artillery cannons.

Over the centuries, a riding school and a hospital were built over Haller Bastion. In 2006, the bastion was renovated and returned to Sibiu’s touristic map.