From the World Heritage inscription:
The landscapes of Cornwall and west Devon were radically reshaped during the eighteenth and nineteenth centuries by deep mining for predominantly copper and tin. The remains of mines, engines houses, smallholdings, ports, harbors, canals, railways, tramroads, and industries allied to mining, along with new towns and villages reflect an extended period of industrial expansion and prolific innovation. Together these are testimony, in an inter-linked and highly legible way, to the sophistication and success of early, large-scale, industrialized non-ferrous hard-rock mining. The technology and infrastructure developed at Cornish and west Devon mines enabled these to dominate copper, tin and later arsenic production worldwide, and to greatly influence nineteenth-century mining practice internationally.
The extensive Site comprises the most authentic and historically important components of the Cornwall and west Devon mining landscape dating principally from 1700 to 1914, the period during which the most significant industrial and social impacts occurred. The ten areas of the Site together form a unified, coherent cultural landscape and share a common identity as part of the overall exploitation of metalliferous minerals here from the eighteenth to twentieth centuries. Copper and tin particularly were required in increasing quantities at this time through the growing needs of British industry and commerce. Copper was used to protect the hulls of ocean-going timber ships, for domestic ware, and as a major constituent of important alloys such as brass and, with tin, bronze. The usage of tin was also increased greatly through the requirements of the tin plate industry, for use in the canning of foods and in communications.
The substantial remains within the Site are a prominent reminder of the contribution Cornwall and west Devon made to the Industrial Revolution in Britain and to the fundamental influence the area asserted on the development of mining globally. Innovative Cornish technology embodied in high-pressure steam engines and other mining equipment was exported around the world, concurrent with the movement of mineworkers migrating to live and work in mining communities based in many instances on Cornish traditions. The transfer of mining technology and related culture led to a replication of readily discernable landscapes overseas, and numerous migrant-descended communities prosper around the globe as confirmation of the scale of this influence.
The Cornwall and West Devon Mining Landscape is a collection of 10 different areas spread mostly across Cornwall and a part of West Devon. The sites include mines, ruined mills, a harbor, and mansions owned by mine owners.
I visited the St. Just area which is the westernmost site located near the city of Penzance. In particular, I toured the Geevor Tin Mine which closed in 1990 and is open to the public. After the mine was shut down in 1990, an effort was made to preserve the facility and open it as a museum. Because of how recently it was shut down, much of the facility remains just as it was during operation.
The photo shown above is of the abandoned Crown Mine, taken about 1 mile away from Geevor outside the village of Botallack.
Visiting this site is possible via public transportation, especially if you travel via bus from Penzance. However, it is best explored by car so you can get to many of the rural locations more easily.