the ann arbor hands-on museum, located in a renovated and expanded historic downtown fire station, contains more than 250 interactive exhibits featuring science and technology. artrain, located on north main street, is a traveling art museum located on a train. a number of other art galleries exist in the city, notably in the downtown area and around the university of michigan campus. several buildings throughout the downtown area, like sweetwaters coffee and tea and the ark, showcase pieces of independent installation art in the form of small "fairy doors". maps of their locations can be found at sweetwaters, peaceable kingdom, or the chamber of commerce.