Built between 1922 and 1926 to pay homage to WWI soldiers, this oft-renovated edifice has been home to everything from civil-rights speeches by Martin Luther King Jr to Brazilian soccer games. It got its latest UFO-landing-upon-a-Greek-ruin look in a controversial 2003 makeover. The Bears now play football here. Hour-long stadium tours are available erratically; check the schedule online.

Before the 2003 renovation, Soldier Field's architecture was so noteworthy it was named a National Historic Landmark. Unfortunately, the landmark lacked corporate skyboxes and giant bathrooms, so the city (the venue is owned by the park district) decided it was time for a change. The new look met almost unanimous derision when it was unveiled; critics quickly dubbed it 'the Mistake on the Lake.' The landmark folks agreed and removed it from their list, saying it jeopardized the National Landmark integrity.