The Hyatt Regency Chicago is a 365-foot-tall (111 m) Hyatt hotel on East Wacker Drive in Chicago, Illinois. The hotel operates over 2,019 guest rooms in two different towers which were constructed in 1974 and 1980. The towers are connected by both an above-ground skyway and an underground concourse. This underground concourse is considered to be part of the Chicago Pedway. The hotel has a multi-level conference center which includes a 25,000 square foot ballroom, and 85,000 square feet of meeting space. The conference center has been home to such events as the 40th, 49th, 58th and 70th World Science Fiction Conventions in 1982, 1991, 2000, and 2012 respectively.