In the Gulf of Finland, a tiny fortified island sits quietly off the coast of Kronstadt, Russia. The Russian military constructed Fort Alexander I in 1845 as a way to guard the waters near Saint Petersburg. Although the fort played a key role in resisting military tensions of the time, it was never used in actual battles. By the late 1800s, the entire island was handed over to the Imperial Institute of Experimental Medicine (currently known as the Institute of Experimental Medicine of the Russian Academy of Medical Sciences), who then converted the fort into a research laboratory for plague and other bacterial diseases. Known as the “Plague Fort,” the facility is currently preserved as a public sightseeing destination that provides mysterious, abandoned spaces to capture by visiting and local Instagrammers alike.