The Church of the Savior on Spilled Blood is one of the main Russian Orthodox churches of St. Petersburg. Also the cathedral is widely known under the name mentioned above, its official name is "the Cathedral of the Resurrection of Christ". The name refers to the blood of the assassinated Alexander II of Russia, who was mortally wounded on that site on March 13, 1881. Construction was ordered in 1883 by Alexander III, as a memorial to his father, Alexander II. The interior was designed by some of the most celebrated Russian artists of the day. It contains over 7500 square metres of mosaics -- according to its restorers, more than any other church in the world. The Soviet government closed the church in the early 1930s. During the Second World War when many people were starving due to the Siege of Leningrad by hostile Nazi German military forces, it was used as a warehouse for food storage. After the war, it was used as a warehouse for a nearby opera theatre. As a result of all these events, the interior was seriously damaged. In July 1970, management of the Church passed to Saint Isaac´s Cathedral and proceeds from the Cathedral were funneled back into restoring the Church. It was reopened in August 1997, after 27 years of restoration. The church never functioned as a full-time worship place, even before the revolution of 1917. Today the church is one of the main tourist attractions in St. Petersburg and also serves as a Museum of Mosaic.

Sources, related links:
Wikipedia - Church of the Savior on Blood