U
- U-plan buildings (34)
- U.S. Department of Veteran's Affairs (1)
- U.S. Presidents (45)
- underground buildings (2)
- underground railroad system (1)
- underpasses (7)
- Unitarian Universalist churches (7)
- updraft kilns (1)
- uranium processing plants (4)
- urban growth (3)
- urban renewal (61)
- utilities (20)
- utility rooms (2)
- utopias (1)