naval port, Leningrad oblast (region), northwestern Russia. It lies on Kotlin Island near the head of the Gulf of Finland. Peter I (the Great) captured the island from the Swedes in 1703 and constructed a fort and docks-then called Kronslot-to protect the approaches to St. Petersburg. Until a channel to St. Petersburg was dredged in 1875-85, Kronshtadt was also a commercial port in which cargoes were transshipped to smaller craft.
Learn more about Kronshtadt with a free trial on Britannica.com.