Portal:Massachusetts/Selected location/12

The Charles River is an 80 mile (129 km) long river that flows in an overall northeasterly direction in eastern Massachusetts. From its source in Hopkinton, the river travels through 22 cities and towns until reaching the Atlantic Ocean at Boston. Thirty-three lakes and ponds and 35 communities are entirely or partially part of the Charles River drainage basin. Despite the river's length and relatively large drainage area (308 square miles; 798 km²), its source is only 26 miles (42 km) from its mouth, and the river drops only 350 feet (107 m) from source to sea.

Brandeis University, Harvard University, Boston University, and the Massachusetts Institute of Technology are all located along the Charles River. Near its mouth, it forms the border between downtown Boston and Cambridge and Charlestown. The river is well known for its rowing, sculling, dragonboating, and sailing, both recreational and competitive. The Head of the Charles Regatta is held here every October, and in early June, the annual Hong Kong Boston Dragon boat Festival is held in Cambridge, near the Weeks Footbridge. For a number of years, the Charles River Speedway operated along part of the river.