Eighth Sister, Unbuilt skyscraper project in Zaryadye, Moscow, Russia

The Eighth Sister is an unbuilt skyscraper project in Zaryadye designed as a 32-story administrative building that would have reached 275 meters tall with a stepped structure and main facade facing Red Square. The proposal was part of Soviet plans to reshape Moscow's skyline during the postwar era.

The 1947 Council of Ministers decree planned a 26-storey building, later raised to 32, on a 15-hectare Zaryadye plot. Work began later and slower than on the other sisters; by spring 1953 the foundation and stylobate were finished, and in 1954 the government halted construction. The architect Dmitry Chechulin saw his attempts to adapt the design rejected, and the erected frame was dismantled for reuse.

The design placed a gilded polyhedral tent with a spire and a USSR emblem on top of the tower, whose upper floors held a showroom with four pavilions. The main entrance hall was a double-height space split into three naves by rows of columns, with cloakrooms for 1,700 people in the side aisles. The main facade faced Red Square, and the plan kept the monuments of Zaryadye standing in landscaped gardens around the building.

The site is now occupied by Zaryadye Park, opened on 9 September 2017. The park's paths and embankment let you trace the footprint of the planned 15-hectare building, bounded by Red Square, Kitaygorodsky Proyezd and Moskvoretskaya Embankment. No trace of the 1947 foundation is visible above ground.

The Rossiya Hotel, built on the abandoned foundation between 1964 and 1967 to Chechulin's design, entered the Guinness Book of World Records as the largest hotel in the world. Its proportions matched the lower five-storey tier of the planned skyscraper, letting observers gauge the intended scale. It was demolished in 2006, and Zaryadye Park opened on 9 September 2017.