Milan is home to two major soccer teams and Italy's largest stadium – San Siro Stadium – where both of them play their home games. San Siro was built in 1925, originally home to just the AC Milan team. In 1947, AC Milan's rivals, FC Internazionale, also moved in. In addition to these top-tier teams, the Italian national team also plays games at San Siro, and it's frequently used as a concert venue for big touring bands. As a football stadium, the capacity of San Siro is now just over 80,000, Italy's largest stadium.
There is a museum at the stadium dedicated to both AC Milan and FC Internazaionale, and when you take a guided tour of San Siro you get to visit each team's locker room.
San Siro is located in the San Siro neighborhood of Milan, west of the city center. It's easily reached by tram (the nearest Metro, Lotto, is still a 20-minute walk from the stadium). Tickets for the museum and tour are €17 for adults, €12 for children 6-14 and seniors (children under 6 are free). Tickets for just the museum are €7 for adults, €5 for children 6-14 and seniors. The museum is open daily from 9:30am-5pm.