The new one? When you use tourism, you get more tourism points for "themes." For example, the Louvre has four art slots and you get tourism for each great work. However, if you have two pieces of art, two pieces of artifacts all from different eras and different civs, you get a bunch more tourism (I think +6). For France, it's doubled in the capital so, if you put the Louvre in Paris and max the theme bonus, it's +12.