The oldest preserved gate in the town of Meersburg has had many names: “Vorderes Seetor”, “Niedertor”, “Kugelwehrtor” and today Unterstadttor. It is said to have been built around 1250, but was not officially mentioned until 1325. Together with its earlier counterpart, the “Hinteres Seetor”, the two town gates were part of the town fortifications and served to defend the town of Meersburg in the Middle Ages. In addition, the gates marked the so-called legal district by which Meersburg was demarcated from its surroundings. In the Middle Ages, in addition to the town wall and market rights, the town also had the town charter, which was granted in 1299 under the rule of Bishop Heinrich von Klingenberg.