Millwall F.C. is a professional football club based in Millwall, a district in London, England. Founded in 1885, the club has a rich history and is known for its passionate fan base. Millwall plays its home matches at The Den, which has a capacity of around 20,000 spectators. The team competes in the EFL Championship, the second tier of English football. The club's colors are blue and white, and its nickname is "The Lions." Millwall has experienced various successes over the years, including reaching the FA Cup final in 2004. The club's rivalry with West Ham United is particularly notable, adding to its competitive spirit.