district, administrative and historic county of Cornwall, England. It lies between Bodmin Moor and the English Channel in southeastern Cornwall; the River Tamar forms the boundary with Devon to the east. The district depends on Plymouth in Devon for many services and is linked to that city by road and rail bridges across the Tamar at Saltash, car ferry at Torpoint, and pedestrian ferry at Cremyll.

Bodmin Moor is formed of a granite intrusion that reaches heights of more than 980 feet (300 metres) and is capped with tors. The valleys on the moor are open, but they become incised and wooded on the granite boundary. The upland is covered with moorland vegetation, and local farmers have extensive grazing rights, used for both sheep and cattle.

Calstock and Gunnislake in the Tamar valley are linked with Plymouth by a branch railway and have become residential areas. The lower Tamar valley is an area of intensive cultivation whose mild local climate is relatively free of frosts. Strawberries and other soft fruits are grown there, and flowers, grown both outside and in greenhouses, are another major source of income. Some early vegetables are cultivated for markets in London and the Midlands, and stock raising (dairy and beef cattle, sheep, and pigs) is also important.

Liskeard is the major market and service centre and has expanded as a residential area, with a small industrial estate to the west. Saltash has developed strong links with nearby Plymouth and is a growth point for light industry and services, as well as for residential development. The south coast is picturesque, with cliffs, sandy bays, and submerged inlets. Small fishing ports have grown at Looe and Polperro, which have expanded as tourist centres, with chalets and sites for tents and caravans (trailers). Area 256 square miles (664 square km). Pop. (2001) 79,647.