Suomenlinna is built on a small island off the coast of Helsinki and is a masterpiece designed by Austin. Built more than 250 years ago, it is one of the largest sea defence military fortresses in the world and the most important and famous attraction in Finland. The Finnish castle also has monuments and historical sites such as churches, military camps, and gates. There are rare marine military relics in the world. In 1991, the Finnish castle was protected by UNESCO's World Heritage List. Suomenlinna is built on a small island off the coast of Helsinki. There is a special small pier on the island called Kauppatori Marina, near the St. John's Church in Helsinki, near the open-air market. (I heard that in the summer, you can also take JT. -Line company's water bus.) Just near the pier, there are several machines for automatic ticket sales. There is also a small ticket house, but no one sells tickets. The role of this pavilion is only used to shelter from the wind? When there is no sunshine, the pier is really cold to the bones. Figure 1 The King's Gate: A symbol of the Suomenlinna, built for military parade between 1753-1754. It is said that the location of the Kings Gate is where the Swedish King Adolf Fredrik anchored the ship when he visited the project in 1752.