The Central City/Black Hawk Historic District is a National Historic Landmark District that encompasses Central City and Black Hawk Colorado. They are adjacent former gold mining camps in the Front Range of the Rocky Mountains in Gilpin County Colorado United States. For a time the area was known as the Richest Square Mile on Earth.The district was designated a National Historic Landmark on July 4 1961. 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?
Answer:
Building