Westfalenhallen (English: Halls of Westphalia) are three multi-purpose venues located in Dortmund, Germany. The original building was opened in 1925, but was destroyed during World War II. New halls were built, the Große Westfalenhalle opened in 1952. The capacity of the arena is 16,500. The Kleine Westfalenhalle served also for balls, exhibitions and concerts, such as the Dortmunder Philharmoniker, until the Opernhaus Dortmund was opened in 1966. The Bundesliga was founded at the Westfalenhallen in 1962.