As the citadel of Sibiu was for centuries a fortress at the gates of Transylvania, it was surrounded by walls and defense towers, most of which still proudly stand: the Council Tower, built in the 13th century, the Harquebusiers' Tower, the Potters' Tower, the Carpenters' Tower, all built in the 15th century, the Thick Tower, erected at the middle of the 16th century, the Haller Bastion, built in 1552, the circular Gunpowder Tower and the Tanners' Tower.
Yüzyıllar boyunca Transilvanya'nın kapılarını koruyan Sibiu kalesi, çoğu bugün bile ayakta olan duvarlar ve savunma kuleleri ile çevrelenmiş durumda: 13. yüzyılda inşa edilen Konsey Kulesi, 15. yüzyılda inşa edilen Harquebusier, Potter ve Carpenter Kuleleri, 16. yüzyılın ortalarında inşa edilen Kalın Kule, 1522'de inşa edilen Haller Burcu, daire şeklindeki Barut Kulesi ve Tanner Kulesi.