What places have you been to that you consider to be a tourist trap. By tourist trap, I mean an area that is geared for tourists and therefore everything is way overpriced.
For example downtown Baltimore is the biggest tourist trap I've seen. Parking is over $20 for just a few hours, the area is relatively small. And there really isn't much unique about the area. The aquarium and science center are way overpriced. For a sunday with your spouse and kids, it will probably cost you over $100 without even thinking about food.
Any other examples?

