The Nikolaitor is the only surviving of the formerly five city gates in Eisenach. It was built around 1170 at about the same time as the neighboring Nikolaikirche and is therefore the oldest city gate in Thuringia. In the Middle Ages , the Via Regia trade route from Frankfurt am Main to Kraków passed through Eisenach. The city gate was closed every evening until 1832.The Nikolaitor was originally built as a gate tower, with the Eisenach town wall and battlement walkways adjoining it on both sides. Around 1307, an outer gate was added to the three main gates Georgentor, Marientor and Nikolaitor about 50 meters in front of the defensive wall. The name Zwinger for this section has survived to the present day. The front gate made it possible to make access to the city even safer. Around 1815, Eisenach's city fortifications were removed step by step, the Nikolai gate tower was retained at the request of the population.