Kennebec Arsenal is a historic arsenal on Arsenal Street in Augusta, Maine. Largely developed between 1828 and 1838 in part because of border disputes with neighboring New Brunswick, it was designated a National Historic Landmark District in 2000 as a good example of a nearly intact early 19th-century munitions storage facility. The arsenal property was garrisoned until 1901, after which it was turned over to the State of Maine as an expansion of the adjacent Maine State Hospital. The state for many years housed mental health patients there.