Cornwall is a ceremonial county in South West England, bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by Devon, the River Tamar forming the border between them. Cornwall is the westernmost part of the South West Peninsula of the island of Great Britain. The southwesternmost point is Land's End and the southernmost Lizard Point. Cornwall has a population of 563,600 and an area of 3,563 km (1,376 sq mi). The county has been administered since 2009 by the unitary authority, Cornwall Council. The ceremonial county of Cornwall also includes the Isles of Scilly, which are administered separately. The administrative centre of Cornwall is Truro, its only city.

Cornwall is noted for its geology and coastal scenery. A large part of the Cornubian batholith is within Cornwall. The north coast has many cliffs where exposed geological formations are studied. The area is noted for its wild moorland landscapes, its long and varied coastline, its attractive villages, its many place-names derived from the Cornish language, and its very mild climate. Extensive stretches of Cornwall's coastline, and Bodmin Moor, are protected as an Area of Outstanding Natural Beauty.

Cornwall forms the tip of the south-west peninsula of the island of Great Britain, and is therefore exposed to the full force of the prevailing winds that blow in from the Atlantic Ocean. The coastline is composed mainly of resistant rocks that give rise in many places to tall cliffs. Cornwall has a border with only one other county, Devon, which is formed almost entirely by the River Tamar, and the remainder (to the north) by the Marsland Valley.

Geology having pressed forward during the present century, at a pace unexampled in other sciences, may reasonably be expected to reach new discoveries in comparatively short intervals of time; these have been reduced, however, almost to instants in respect to Cornwall. After the very able, minute, and laborious investigation made by Doctor Boase, of every district, of every parish in the whole county, the work of discovery would seem to have been completed, at the least for several years; but Mr. de la Beche came soon afterwards into Cornwall, under the sanction of Government, assisted by officers of the Engineers employed on the great Trigonometrical Survey; and this eminent Geologist has, in consequence, been enabled to lay down the various main lodes, the cross courses, the elvans, &c. together with the junctions of granite, greenstone, and killas, with an accuracy and discrimination never before attained, nor ever approximated to, except by Mr. Richard Thomas, in his survey of the mining district, made about twenty years ago.

In continuation of the same trains of reasoning and of thought, Mr. Fox has been led to investigate the important elements of variation and dip of the magnetic needle; and in pursuing these inquiries, he has invented an instrument possessed of far greater accuracy than any one previously employed, and which at this moment is in actual use, through the enlightened liberality of our own and other governments, in various and distant portions of the globe.