This Google Map is mapping the locations of history, art and architecture in the public realm. The project was started in New York, and has mapped a huge number of cultural locations in the city, but now also shows cultural landmarks across the USA.
It is possible to search the map by category (and there are a lot of them). So, for example, it is possible to refine a search for art galleries, museums or historic buildings etc. If you click on a map marker you can get more information about the listing.
Each listing also includes a list of other nearby cultural locations.