Uspenski Cathedral sits on a hill in Helsinki's Katajanokka district. Its russet-red brick walls are topped by fourteen green and gold onion domes, the largest rising over thirty-three metres, roughly the height of an eleven-story building. It is the largest Orthodox cathedral in Western Europe. Its name is drawn from the Old Church Slavonic word for the Dormition of the Virgin Mary.

Its construction was a genuinely international affair. In 1814, Tsar Alexander I set aside fifteen percent of the salt import tax to fund two new churches for Finland's capital, one Lutheran, one Orthodox. Russian architect Aleksey Gornostayev designed the cathedral but died before seeing it finished in 1868. Its 700,000 bricks were shipped across from the dismantled Bomarsund Fortress, a relic of the Crimean War.

VoiceMap's self-guided audio tours pair the cathedral with the neoclassical Senate Square nearby, tracing Helsinki's shifting allegiances between Sweden, Russia and Finnish independence.