The Spurwink River is a 4.6-mile-long (7.4 km) primarily tidal river in Cumberland County Maine in the United States. It rises in the town of Cape Elizabeth and flows west then southwest through salt marshes to its mouth at the Atlantic Ocean. It is bridged by Maine State Route 77 at the river's approximate halfway point. From a point shortly above the bridge to the river's mouth it forms the boundary between Cape Elizabeth to the east and the town of Scarborough to the west. 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?
Natural Place