Look inside: Northwestern Mutual tower, hidden gems highlight latest Doors Open Milwaukee

Despite the early fall heat wave that hit the Milwaukee-area this weekend, thousands of residents packed the streets to take part in Doors Open Milwaukee and get a look inside many of the city's most famous buildings, such as new Northwestern Mutual headquarters and the Federal Courthouse. Check out the attached slideshow to see some of the buildings that were part of the popular event and some of their unique features.