Tolstaya Margarita Tower - a cannon tower built in 1529 near the Great Sea Gate, is one of the most impressive defense structures of the Old Town of Tallinn. Along with the Sea Gate, the Tolstaya Margarita tower served as an outpost covering the approach to Tallinn from the sea. Until 1842, the tower was called the New Tower, as it was built on the site of the destroyed first watchtower of the Great Sea Gate, and from the middle of the XIX century, due to the thickness of its walls, it became known as Fat Margarita. The wall thickness in some places reaches 6.5 meters, the height of the structure is 20 meters, and the diameter is 25 meters. When the gun turret lost its defensive significance, it was used as a barracks, warehouse and prison. In 1917, a strong fire broke out in the tower, significantly damaging the structure. For more than 60 years, the building stood in a dilapidated state, without a roof and with walls bearing the traces of a fire. After the restoration, in 1981 the exposition of the Estonian Maritime Museum was opened in the tower Tolstaya Margarita. The four floors of the tower feature unique exhibits introducing the history of Estonian navigation and shipbuilding. The museum’s collection contains old lots and compasses, models of sailing ships and modern ships, sea charts, documents, photographs, archaeological finds, raised from the bottom of the Baltic Sea. Visitors can see a stand with various types of sea knots, a collection of fishing tackle, one of the first diving suits, ship bells, helms and much more. The observation deck is equipped on the roof of the tower with a beautiful view of the Old Town, the Baltic Sea and the Port of Tallinn. In the summer, the only rooftop cafe in the Old Town operates here. The image of the Fat Margarita tower can be found on postcards, in photo albums and tourist guides in Tallinn. Thick Margarita is one of the most recognizable and visited attractions in the capital of Estonia.