Kronshtadt (Kotlin Island), to the west of St. Petersburg, was developed between 1703 and 1704 by Peter the Great as a base from which to defend St. Petersburg and to attack the long-standing enemy of the Russian empire, the Swedish navy. For a long time it was the only military harbor of the empire, which is why it was off-limits to all but its permanent residents; visitors were stopped at special checkpoints as late as 1996. Today anyone can visit, either by taking a "Meteor" hydrofoil, which departs from St. Petersburg, or by taking an excursion from one of the agencies on St. Petersburg's Nevsky prospekt.
In the first half of the 20th century the Kronshtadt Commune aimed to break the monopoly of the Communist Party and to give back to peasants the right to use their land freely. The revolt lasted two weeks, seriously jeopardizing Lenin's hold on power, but was finally bloodily repressed. Despite this uprising, the streets of Kronshtadt are still named after Marx and Lenin, and the town still seems to live in the past, as if to hold on to the mighty era of the Soviet military machine. Meanwhile, once closed for foreign and even Soviet public access because of its military status, Kronshtadt is still proud of its naval pedigree. Its significance was gradually diminished by the development of St. Petersburg throughout the 19th century, but there are still military and scientific vessels using its harbors. Sights include Naval Cathedral; a lovely embankment overlooking the Gulf of Finland and the modern Russian navy ships moored at the piers; the Gostinny Dvor (one of Kronshtadt's first buildings and now a department store in need of renovation); the Summer Garden; and the Menshikov Palace, now a club for the island's sailors. Off the shore are several forts that were constructed during the Crimean War (1853–56). The most interesting of these is Fort Aleksandr, which in the 19th century was turned into a laboratory to research the bubonic plague. These days it's a favorite stop-off point for yachters.