Bayer 04 Leverkusen, also known as Bayer Leverkusen, Leverkusen or simply Bayer, is a German football club based in Leverkusen, North Rhine-Westphalia. It is the most well-known former department of TSV Bayer 04 Leverkusen, a sports club whose members also participate in athletics, gymnastics, basketball and other sports including the RTHC Bayer Leverkusen (rowing, tennis and hockey). In 1999 the football department was excluded from the club and called the Bayer 04 Leverkusen GmbH. Bayer Leverkusen's local rivals are the 1. FC Köln.