Dallas City Hall is a bold piece of 1970s civic architecture by I. M. Pei, shaped like an inverted pyramid set back from a broad plaza. Its concrete form is severe, but it has become one of the city's most recognisable modern buildings.
The building is mainly worth a stop if you are interested in architecture or already walking through downtown Dallas. The best view is from the plaza, where the full tilt of the facade is easiest to read.