The Washington Park Historic District is a historic district in the village of Newtonville in Newton Massachusetts. It includes the following properties some of which date from the 1890s: 4 to 97 Washington Park plus 5 and 15 Park Place. The focal point of the district is the city park which is located in the median of the street of the same name. On March 12 2008 it was added to the National Register of Historic Places. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Building