The medieval city wall with many towers is the hallmark of Tallinn. Powerful fortifications built around the city in the 13th-16th centuries turned Tallinn into a well-defended impregnable fortress. The length of the city wall with 46 defensive towers reached 2.4 km, and the height was 16 m. Until now, 26 defensive towers, 2 intermediate gates, parts of two front gates and a section of the wall with a length of about 1.9 km have been preserved. The surviving city defense system includes the high Küster tower, the massive Fat Margarita tower, the Sea Gate complex, the Maiden Tower, the towers Kik-in-de-Kek, Kuldjala, Sauna, Nunna and Epping. At present, museums are open in many towers, and you can take a walk on the section of the wall between the Nunne, Sunna and Kuldjala towers. The best way to view the city wall is from Patkuli Viewpoint, as well as from Tower Square.