Kazan Cathedral "After the Russian Revolution of 1917 the authorities closed the cathedral (January 1932). In November 1932 it reopened as the pro-Marxist "Museum of the History of Religion and Atheism". Services resumed in 1992, and four years later the cathedral was returned to the Russian Orthodox Church." (Wiki)

In 1919 the church of St. Casimir was returned to the Catholics, but was damaged again during the Second World War, closed down and in 1963 converted into a Museum of Atheism. The church was reconsecrated in 1991" (Wiki)

The Dominican Church: After World War II the complex was occupied by the Soviets, used as warehouse and in the 1970s changed into a museum of religion and atheism. With the collapse of the Soviet Union the church was given to the Ukrainian Greek Catholic Church and now serves as a parish church. The monastery, however, has not yet been returned and still serves as a museum (renamed The Lviv Museum of History of Religion). (Wiki)

"Originally designed as a place of Islamic instruction in 1905, the Matpana Baya madrassah was transformed into a museum of atheism under the Soviets before being changed again after independence into a museum of religion"