In the early 1970s, Russian architect Evgeny Stamo and engineer Alexander Markelov came up with plans for an unusual house in the capital city Moscow. The house was to be shaped like a ring, about 150 meters across, enclosing a large inner courtyard with playgrounds and green spaces. The building was to have over nine hundred apartments, and all the necessary services and facilities, including shops, a pharmacy, a laundry room, a studio, post office, and so on. When completed in 1972, the authorities were so impressed that plans for more such house across Moscow were drawn up.

Photo credit: Marcel Sardo/Twitter