The Metacomet Ridge, Metacomet Ridge Mountains, or Metacomet Range of southern New England is a narrow and steep fault-block mountain ridge known for its extensive cliff faces, scenic vistas, microclimate ecosystems, and rare or endangered plants. The ridge is an important recreation resource located within 10 miles (16 km) of more than 1.5 million people, offering four long-distance hiking trails and over a dozen parks and recreation areas, including several historic sites. It has been the focus of ongoing conservation efforts because of its natural, historic, and recreational value, involving municipal, state, and national agencies and nearly two dozen non-profit organizations.

Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relatively uniform lithology. The largest of these fault blocks are called crustal blocks. Large crustal blocks broken off from tectonic plates are called terranes. Those terranes which are the full thickness of the lithosphere are called microplates. Continent-sized blocks are called variously microcontinents, continental ribbons, H-blocks, extensional allochthons and outer highs.