The Marquette Building is one of the Loop's great early skyscrapers, a 1890s office block whose muscular exterior sits comfortably among Chicago's better-known commercial landmarks. Step inside for the lobby: Tiffany mosaics, bronze work, and scenes from the life of Pere Marquette turn a working building into a quick but worthwhile architecture stop.
It is still an office building, so the visit is about the public lobby rather than a full tour. Pair it with the nearby Rookery and Monadnock blocks for a compact walk through Chicago's first skyscraper age.