The Church of the Three crosses in Imatra is a masterpiece of modern architecture by Alvar Aalto. This church was completed in 1957. It is said to be Aalto's most original church design. It is named after the three white crosses at the altar. The building consists of three consecutive halls which can be separated by sliding walls; this enables parts of the church to be used for parish activities during the week. The exterior of the church is white with a copper roofing. DOCOMOMO has listed the church as a significant example of modern architecture in Finland.