The Haller Bastion (Bastionul Haller) is one of the largest surviving artillery bastions of Sibiu, forming part of the southern fortifications along Bulevardul Corneliu Coposu.
Construction began in 1551 during the mayorship of Petrus Haller, when Sibiu was adapting its medieval defenses to withstand increasingly powerful cannon fire. Austrian general Giovanni Battista Castaldo initiated the project, with architect Alessandro Clippa and master builders Peter Nürnberger and Georg Waal carrying out the work. The main structure was completed in 1553, followed by final work in 1558 after an interruption caused by a plague epidemic.
Built in brick and packed with earth, the bastion was designed as a massive artillery platform rather than a conventional medieval tower. Its walls extend for more than 220 meters and reach around 9 meters in height, forming a broad spearhead shape that projects beyond the defensive line. Stone projections near the top were intended to prevent attackers from placing scaling ladders against the wall, while several cannon openings remain visible on the sides facing the Thick Tower and Strada Manejului.
The interior of the bastion gradually acquired new uses after its military role declined. A riding school was built here in 1771, and the site was later redeveloped for medical use. The present hospital building was completed in 1914 for a state institute that trained midwives and subsequently served as a maternity and obstetrics clinic. Since 1984 it has housed neurological services, rising above the broad interior of the historic bastion.
