Fort Alexander I

Fort Alexander I is an oval, multi-tiered artillery sea fort built between 1838 and 1845 in the Gulf of Finland off Kronstadt, part of the ring of fortifications defending the approaches to St Petersburg. Named after Emperor Alexander I, its massive stone-and-brick casemates never saw combat and were soon outdated. From 1899 to 1917 the isolated fort was repurposed as a laboratory for the study and prevention of plague, where Russian scientists produced anti-plague and other sera. Its separation by water made it a natural quarantine, and it became popularly known as the "Plague Fort" (Chumnoy fort).

The combination of contagion research and the deaths of researchers gave the fort a bleak reputation, later amplified when it stood derelict and, in the 1990s and 2000s, hosted informal parties. Urban explorers and boat visitors have long described an oppressive, uneasy atmosphere within its damp corridors. Such impressions are anecdotal and subjective, a reputation shaped by the building's grim past rather than any documented phenomenon.

Beyond the legend, Fort Alexander I is a striking example of nineteenth-century maritime fortification and a sobering monument in the history of medicine, marking the early years of Russian bacteriology and vaccine production. It is now being restored as a cultural venue within the wider Kronstadt heritage programme.

For decades the fort was accessible only by water and stood empty and decaying, visited informally by boat excursions from Kronstadt and St Petersburg. Since the early 2020s it has undergone major restoration as part of the "Island of Forts" tourism and heritage cluster, which aims to reopen it as a museum and cultural centre.

During works, access to the interior is restricted and independent landings are not generally permitted; visitors should rely on official excursions and check current arrangements before travelling. The historic masonry and stairs have long been unstable, so the site should be treated with due care and respect for its restoration.