Fort 'Grand Duke Konstantin' in Kronstadt, founded in 1808 in response to the threat from the English fleet in the Baltic Sea, is an important historical monument. Today it functions as a terminal and checkpoint for small vessels.

Originally, the fort was a two-tier wooden battery with 45 guns for coastal defense. In 1824, after a flood, the battery was restored, and in 1834 a caponier was added for protection against rear attacks. Emperor Nicholas I renamed the battery to Fort 'Konstantin' in honor of his son in 1834.

In the 1850s, the wooden structures of the fort were dismantled, but the construction of a new stone battery was delayed due to the Crimean War. After the war, in 1858, the construction of an escarpment wall made of granite boulders began, completed in 1861. In 1863, the fort received armored parapets for gun protection, which was an innovative solution.

In the 1870s, the fort was modernized: new guns were installed, barracks were built, and a pavilion for an optical rangefinder was constructed. In 1890, the fort was connected by a causeway to Kotlin Island, and in 1896 and 1901 it underwent reconstruction, including the replacement of outdated guns.

In 1909 and 1911, additional guns were installed on the fort, but it did not participate in World War I. After the revolution, the fort was renamed 'K'. In the 1930s, new defensive structures appeared on it, which were used during the Great Patriotic War.

In the 1960s, the fort was disarmed and looted. In the 1980s, a bus depot was established on its site. From 2000 to 2007, electronic music festivals were held at Fort 'Alexander', and dance floors were organized at Fort 'Konstantin'.

In 2010, a decision was made to establish a checkpoint at Fort 'Konstantin' for small vessels crossing the state border. In 2012, this checkpoint was officially put into operation.