The Friedrichsburg Gate was part of the Friedrichsburg Fortress, which defended Konigsberg from the left bank of the Pregel River. The capital of Prussia has been built as a fortress city since the 13th century. For 7 centuries, fortified structures were erected and improved in Konigsberg. Nowadays, the Friedrichsburg Gate is a museum. 

The city of Konigsberg was founded in 1255 near the island of Kneiphof, on the right bank of the Pregel River. The castle was located opposite Kneiphof Island (now it is called Kant Island). Fortified fortress walls were constantly erected around the Old Town and the island, as it grew. Until the 15th century, they had the appearance of a medieval fortress, but with the advent of artillery, it became necessary to build a bastion-type fortress.  

Friedrichsburg became such a fortress. It was founded in 1657 on the left bank of the Pregel River. Over the course of two centuries, the fortress expanded and strengthened. The Friedrichsburg Gate was built only in 1852 by architect Christian Otter.  
The fortress became a key element of the fortifications of Koenigsberg. At the beginning of the 20th century, most of the medieval walls and ramparts were eliminated, as they hindered the development of the modern city, but many gates were preserved as sights of Konigsberg.  

It was decided to leave the main Friedrichsburg Gate from the Friedrichsburg fortress. The Brandenburg Gate, the Royal Gate and the Don Tower, where the Amber Museum is now located, were also preserved. 

During the WWII, the Friedrichsburg Gate was badly damaged. However, they were not dismantled, like most buildings of the Prussian era, since the gates were located on the closed territory of the port warehouse. In 2011, the Friedrichsburg Gate was restored and opened to the public. 

The Friedrichsburg Gate has a neo-Gothic appearance. They are lined with red facade bricks. Inside the Friedrichsburg Gate, a museum exhibition "Ship Resurrection" has been created, which is dedicated to the creation of the navy in the era of Peter I. The exposition is part of the collection of the Kaliningrad Museum of the World Ocean.  

The main exposition of the Museum of the World Ocean is located on the opposite bank of the Pregolya River. There you can see the Main Building of the Museum, as well as expositions on ships. There is an exposition dedicated to the space industry on the Cosmonaut Patsaev Ship, and on the Vityaz ship-museum you can see an interesting exposition dedicated to oceanographic research.