City Hall's Green Roof by David B. GleasonThe City of Chicago's website has more information than you probably need.

Something we love about Chicago is the green roof atop the city hall, which is unfortunately not open to the public. You can see people walking through the rooftop garden in the photograph on your right.

In the event of an emergency, dial 9-1-1.

In person or by mail

City Hall
121 N. LaSalle Street 
Chicago, Illinois 60602

By phone

Dial 311 (within Chicago city limits)

If calling from outside of Chicago,
dial: 312.744.5000