East Rock of south-central Connecticut, United States, with a high point of 366 feet (112 m), is a 1.4-mile (2 km) long trap rock ridge located primarily in the neighborhood of East Rock on the north side of the city of New Haven. A prominent landscape feature and a popular outdoor recreation area with cliffs that rise 300 feet (91 m) over the city below, East Rock is part of the narrow, linear Metacomet Ridge that extends from Long Island Sound near New Haven, north through the Connecticut River Valley of Massachusetts to the Vermont border. East Rock is the central feature of East Rock Park, a municipal park owned by the city of New Haven along the New Haven-Hamden town line.
East Rock
East Rock with its eponymous neighborhood below
East Rock, New Haven, an 1872 engraving showing the Mill River, with New Haven in the distance
View south from East Rock in winter.
Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro. Trap is also used to refer to flood (plateau) basalts, e.g. the Deccan Traps and Siberian Traps. The erosion of trap rock created by the stacking of successive lava flows often created a distinct stairstep landscape from which the term trap was derived from the Swedish word trappa, which means "stairway".
The East Rock trap rock ridge overlooking New Haven, Connecticut, U.S.
Trap rock forming a characteristic pavement, Giant's Causeway, Northern Ireland
Trap rock cliff overlooking the Hudson River from an overlook on the Hudson Palisades in Bergen County, New Jersey, U.S.
Trap rock forming a characteristic stockade wall, Giant's Causeway, Northern Ireland