The Regierungsbunker near Ahrweiler is one of the most revealing Cold War sites around Bonn. Built to shelter the West German government in the event of nuclear war, the tunnel complex has been partly preserved as a museum, with blast doors, command rooms, bunks, and the heavy practical imagination of catastrophe.
It is outside Bonn proper, but the connection is direct: this was infrastructure for the old capital. The guided visit is sobering rather than fun, and that is its strength. It turns abstract Cold War politics into corridors, machines, and the logistics of survival.