Sibiu retains more of its medieval defensive circuit than almost any other city in Transylvania. Three rings of fortifications were built between the 13th and 15th centuries, and significant portions of the inner and outer walls, along with several bastions and towers, survive in good condition. The most impressive are the Carpenters' Tower, the Potters' Tower, and the Harquebusiers' Bastion, which have been restored and are visible from the streets below the old city.
Walking the Lower Town — the working-class suburb below the original Saxon upper city — gives the best views of the walls. Several of the towers can be entered; the Carpenters' Tower houses a small exhibition on the city's fortification history.