Rattlesnake Mountain is a traprock mountain, 750 feet (230 m) above sea level, located 9 miles (14 km) southwest of Hartford, Connecticut in the town of Farmington. It is part of the narrow, linear Metacomet Ridge that extends from Long Island Sound near New Haven, Connecticut, north through the Connecticut River Valley of Massachusetts to the Vermont border. Rattlesnake Mountain, a popular outdoor recreation resource of the metropolitan Hartford area, is known for its cliff-top scenic vistas, unique microclimate ecosystems, and rare plant communities. Will Warren's Den, a boulder cave located on the mountain, is a local historic site. Rattlesnake Mountain is traversed by the 51-mile (82 km) Metacomet Trail.