Someone who visits a city, town, or historic site just for the pleasure of exploring it can be described as a tourist.
When you travel for fun, you're a tourist. Some local inhabitants of vacation destinations might have a negative image of obnoxious, camera-toting tourists, but really they're just travelers who are curious about different parts of the world. Beaches, amusement parks, castles, and big cities are all places you're likely to run into tourists. The term "tourist trap," or a place that exists only to take tourists' money, was first used in 1939 by the novelist Graham Greene.