FK Zeljeznicar is a professional soccer club based in Sarajevo, Bosnia and Herzegovina. Founded in 1921, the club has a rich history and is one of the most successful clubs in the country. They play their home matches at the Grbavica Stadium, which has a capacity of around 13,000 spectators. The club is commonly known by its nickname "The Blues" due to their traditional blue and white striped kit. Zeljeznicar has won numerous domestic titles, including six Bosnian Premier League championships and five Bosnian Cups. They have also had success on the European stage, reaching the quarter-finals of the UEFA Cup in the 1971-1972 season. The club has a passionate fan base and enjoys a fierce rivalry with FK Sarajevo, known as the "Sarajevo Derby."