The Charles River, sometimes called the River Charles or simply the Charles, is an 80-mile-long (129 km) river in eastern Massachusetts. It flows northeast from Hopkinton to Boston along a highly meandering route, that doubles back on itself several times and travels through 23 cities and towns before reaching the Atlantic Ocean. The indigenous Massachusett named it Quinobequin, meaning "meandering" or "meandering still water".

Hopkinton is a town in Middlesex County, Massachusetts, United States, 25 miles (40 km) west of Boston. The town is best known as the starting point of the Boston Marathon, held annually on Patriots' Day each April, and as the headquarters for the Dell EMC corporation.