Possible Clues:

• Building over frozen soil, diverting river to the west
• Reportedly signed beneath a building
• A cylindrical building, usually domed
• Capitol hall
• Tour and review domed building
• Building in which you can't be cornered?
• Duke after round cask in Royal Academy building
• Capitol topper
• Round, domed building
• Grade II-listed building in Birmingham’s Bull Ring, completed in 1965