You are probably aware of my list of maritime museums in Europe.
Americans and American travel agencies seem to be overcautious and look upon anything outside the US borders as being strange and potentially dangerous.
It is worth remembering that the risk of being subject to pick-pockets and other tourist associated crime is higher if you act as a tourist or move in tourist areas.
I have travelled off the beaten path in many parts of this world, walking or travelling with public transport, and never experienced anything to talk about.