The City Wall can be visited
Town Fortification Drosendorf

The Drosendorf town fortification in the northern Waldviertel of Lower Austria is one of the best-preserved medieval town walls in the country. It encircles the entire old town of Drosendorf-Zissersdorf, which rises on a mountain spur in a loop of the Thaya river.
History+
The origins of the fortification date back to the mid-13th century, when a first town wall was erected. At the two town gates, the Horner Tor and the Raabser Tor, this wall was about eight meters high with a thickness of 1.5 meters. Between 1260 and 1300, two habitable towers were built at the Horner Tor. Shortly thereafter, another tower was added west of the Raabser Tor, but it was demolished in the 19th century. In light of the battles for the city in 1405 and the subsequent Hussite Wars, the wall was reinforced and expanded to a height of about ten meters and a thickness of 1.9 meters by the first decades of the 15th century. A round tower even received three-meter-thick walls to withstand artillery fire.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Stadtmauer_Drosendorf_0841.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 48.8673, 15.6195