The Safe House, Milwaukee, US
Information about this spy-themed Milwaukee bar is hard to come by, which is exactly the way the owners want it. There's no sign outside - just a wall plaque for International Exports Ltd, the bar's cover name - and visitors are asked for a password before entering through a secret door. Customers who don't know the code are made to do a dance on the spot, with the results filmed by hidden cameras and shown on huge wall-mounted screens inside the bar.
Within the nondescript building, there are secret passages, two-way mirrors, spy holes built into the walls and telephone booths with background noise for "agents not wishing to reveal their exact location".