It is also Saint Petersburg's main seaport. In March 1921, it was the site of the Kronstadt rebellion.
Traditionally, the seat of the Russian admiralty and the base of the Russian Baltic Fleet were located in Kronstadt guarding the approaches to Saint Petersburg. The historic centre of the city and its fortifications are part of the World Heritage Site Saint Petersburg and Related Groups of Monuments.
Kronstadt has been a place of pilgrimage for Orthodox Christians for many years due to the holy memory of Saint John of Kronstadt. Bus and water tours to Kronstadt are taken daily from Saint Petersburg.
Kronstadt was founded by Peter the Great, whose Imperial Russian forces took the island of Kotlin from the Swedes during the Great Northern War in 1703. The first fortifications were inaugurated on 18 May 1704.