Merikasarmi (originally Katajanokka Barracks) is a barracks area originally built for use by the Russian military in Katajanokka, Helsinki, in 1816-1820. It is currently housed in the building of the Finnish Ministry of Foreign Affairs. The barracks were designed by the architect Carl Ludwig Engel. Before the Ministry of Foreign Affairs moved to the area in the late 1980s, the buildings were renovated and partly rebuilt according to the plan of Professor of Architecture Erik Krakström.
To the north of the Sea Barracks, the ice-breakers of the Finnish state are located near the Katajanokka quay.
Merikasarmi is located on the northern bank of the Katajanokka River near the end of the peninsula. In Katajanokka, in the area of the current Katajanokka Casino, a cannon battery was already installed in 1721 during the Uusikaupun World War II. Later artillery was installed in Helsinki, especially in Viapori. In 1812 it was decided to use artillery yard as a base for barracks. Johan Albrecht Ehrenström was the designer of the plan for the capital city of Helsinki.
Financing of buildings came from Russian Empire by order of Alexander I in 1816. Carl Ludwig Engel arrived in March 1816 to design the building, and three months later it was ready for presentation to Nicholas I. In 1826 two winged outbuildings were ordered: a kitchen wing and a wing to house officers. These annexes were mainly completed by 1838. The section of the wing was completed at the western end of the barracks in 1825, but the east wing, designed by Engel, was not built at this stage. In the early years, the barracks Katajanokka held Orthodox worship services. The first soldiers of the barracks were the land forces of the Russian Empire.
In 1832 the barracks were transferred to the Finnish naval base, which was established two years earlier. Thus the area, which was originally called the Katajanokka barracks, was called sea barracks. However, the Finnish Navy, a naval unit, was abolished in 1880, when the army of the Grand Duchy of Finland passed from professional to conscription. After that the barracks were again used by the Russian military, and the area became a strong base for the Russian Baltic Fleet. The governors-general of the Grand Duchy of Finland in Helsinki considered the Katajanokki barracks as an unhealthy climate for Russian soldiers.
After the independence of Finland, Merikasarmi became available to the Finnish Navy. The Finnish Navy headquarters were in the area until 1958. The Naval Battalion was used by the Guards Battalion until 1968, when it moved to Santahamina and Taivallahti.
In 1972, the Government of Finland decided to transfer the building to the Ministry for Foreign Affairs of Finland, which was not implemented until the end of the 1980s. The last military facilities there will still be in operation between 1980 and 1985. In the Electrical Engineering Department of the General Staff and the Post Office. Founded after World War II, Valmet has kept its shipyard in the area and left Mérikasarm in Vuosaari in 1975.
The garrison and later Valmeta shipyard used a large area at the eastern end of Katajanokka. Around the barracks there were several brick and wooden household and storage buildings. After the shipyard left this area, a residential area known as the "new side" of Katajanokka was built to the south and east of the barracks. However, some of the old brick buildings on the western side of the barracks have been preserved and are now home to a primary school, among others.
Between January 1986 and September 1989, the Ministry of Foreign Affairs moved to Merikasarm from 22 different districts of Helsinki.
In 2009, according to President Marty Ahtisaari, the courtyard between buildings C and G of the sea barracks, i.e. the courtyard, was named Marty Ahtisaari Square. The original purpose of the square was to serve as a garrison training ground and a ceremonial courtyard.
In November 2018, the largest reconstruction in the history of the building began in Merikasarm. The aim of the renovation is to make the premises more modern and suitable for office use, while at the same time, among other things, all building technologies in the building will be restored. After the renovation, there will be more than 800 employees in the building instead of the previous 400. The renovation will be carried out with NCC . The cost of the renovation is estimated at around 88 million euros.