Saint Basil's Cathedral (Intercession Cathedral)

Saint Basil's Cathedral — officially the Cathedral of the Intercession of the Most Holy Theotokos on the Moat (Intercession Cathedral) — stands on the southern side of Red Square and ranks among the most recognizable monuments of Russian architecture. It was built in 1555–1561 on the orders of Tsar Ivan the Terrible to commemorate the capture of Kazan in 1552. The name "on the Moat" refers to the defensive Alevizov Moat, which ran along the Kremlin wall and was about 13 meters deep and 36 meters wide.

The cathedral unites eleven churches on a single foundation platform. The central tented church is dedicated to the Intercession of the Most Holy Theotokos, while the eight churches surrounding it are dedicated to saints whose feast days coincided with the decisive battles of the Kazan campaign. The height of the central tent is 47.5 meters, and from the ground to its top it measures 65 meters, even though the cathedral has no deep foundation — it stands on an artificially raised mound on the site of the former moat. According to a widespread version, the builders were the Russian master builders Barma and Postnik, though a number of historians believe these names refer to a single master; there is also a hypothesis that a Western European architect took part. The legend that the master builders were blinded on the tsar's orders has no documentary confirmation.

In 1588 a tenth church was added to the cathedral over the burial place of the venerated Moscow holy fool Basil the Blessed, from whom the cathedral took its popular name. In 1672 an eleventh church was added in honor of another holy fool, John of Moscow; it remained closed from 1929 and reopened to visitors only in November 2018 after restoration. In 1812, during the occupation of Moscow, French troops kept horses in the cathedral's undercroft and looted its sacristy; a legend has survived that Napoleon intended to blow up the building.

From 1918 the cathedral was placed under state protection as a monument; in 1923 a museum of history and architecture opened inside it, and since 1928 it has been a branch of the State Historical Museum. Services were halted in 1929 and resumed only in 1991; since 1997 they have been held regularly on Sundays in the chapel of Basil the Blessed. The cathedral twice escaped demolition planned during the Soviet era in connection with the reconstruction of Red Square, reportedly, according to legend, thanks to the personal intervention of Joseph Stalin. Since 1990 Saint Basil's Cathedral, together with the Kremlin and Red Square, has been included on the UNESCO World Heritage List, and its belfry holds one of the largest working collections of bells in Russia.