Gargantuan home of Russian science.

The avant-garde design was able to bypass strict Soviet regulations on architecture.

Former headquarters of the KGB.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

A model village fit for an emperor.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

This 15th-century cave complex is one of the very few monasteries to stay open throughout World War II and the Soviet regime.