The Carbide & Carbon Building in Chicago, an Art Deco tower used for various film/tv locations, including Batgirl's lair in the Arrowverse.
Look! It's Batgirl's lair! (At least if you're in the Arrowverse.) This is a very cool #chicago art deco tower, the Carbide & Carbon building. If a #Kolchak episode wasn't filmed there, it should have been.