Błękitny Wieżowiec (literally Blue Skyscraper) is a building located in Bank Square in Warsaw. It stands in the place that was occupied before World War II by Warsaw's largest synagogue, the Great Synagogue, which was blown up by the Germans in 1943. Initial concepts for the construction of the skyscraper had been put forward in the 1950s, but construction finally began in the 1970s and was suspended shortly after the main structure was built.