Wheal Vor sits on the south flank of Tregonning Hill, the most easterly of the Cornubian granite intrusions before the land falls away toward the Lizard. The granite is mineralised at depth with tin and copper, and small-scale extraction here probably goes back to the medieval period. By the eighteenth century the workings had consolidated into one of the most productive mines in west Cornwall, dipping under the rolling fields above the village of Breage and the small town of Helston a few miles north. At its peak Wheal Vor's lodes yielded an estimated £2,000,000 worth of tin — a figure recorded in the contemporary mineral statistics compiled by Robert Hunt of the Geological Survey. The profits made fortunes for the Cornish gentry whose shares it carried, and supported the working life of an entire parish for the better part of a century.

Every deep mine in Cornwall fought water. The granite was permeable enough through its joints and the surrounding killas mudstones absorbent enough that pumps had to run continuously just to keep the shafts dry. Wheal Vor's solution was the largest pumping engine available: a Harvey and Co. Cornish beam engine, built at the foundry at Hayle a few miles north, capable of lifting tons of water per stroke. Harvey was itself a shareholder in the mine, so the engine and its mine were close kin. The starting was an event; the whole parish turned out. But by the 1850s the coal bill was unsustainable, and the mine had been deepened past the point where the existing engines could match the inflow. In 1860 the engines were stopped and the workings were left to flood. Limited operations restarted in 1885 with a new engine built to extract tin from the accumulated waste in the valley; until that engine started, Wheal Vor had been employing only twenty-two people, more by sentiment than economics. A fuller reopening followed in 1906, with sixty-five workers and sixteen of them underground. Some black tin was produced between 1907 and 1910. Then water beat the new operation too, and the mine closed once more.

The story did not quite end. Twentieth-century attempts to reopen Wheal Vor ran into a complication peculiar to old English land: the deeper parts of the mine ran under property that the Duke of Leeds owned. The major shareholding, held by the cooperative Treworlis Estate, was tractable; the Leeds Estates were not. Negotiations dragged. Then in the early 1960s the eleventh Duke of Leeds died, and within a year his successor died too, without an heir, in 1964. The estate had to be sold. The sale dragged years further. Every project to drain and reopen the mine foundered on the legal complication of paying the right person to mine under their fields, and by the time the question was settled the worldwide tin price had fallen back through the level that would have justified the investment.

Since 2006 the Wheal Vor site has formed part of the Tregonning and Trewavas Mining District, one of ten components of the Cornwall and West Devon Mining Landscape that was designated a UNESCO World Heritage Site in that year. The engine houses survive as roofless granite skeletons among the gorse on Tregonning Hill, and the dressing floors below — where ore was crushed, washed, and sorted by hand by women and children in the nineteenth century — are visible as platforms cut into the slope. The Trevithick Society published a full history of the workings, titled Great Wheal Vor, in October 2015. The mine still owns its tin, in the sense that the lodes are intact and only sealed under their own water. Tin prices in 2025 are well above the level that ended the mine. But Wheal Vor is not on anyone's current list to reopen; the geometry of the workings, the unresolved legal threads, and the cost of dewatering a mine that has been underwater for a century and a half make it economically theoretical.

From the air the mine is best read as a pattern of roofless stone among the bracken on the south slope of Tregonning Hill, three miles inland from the south Cornish coast. Look for the line of small valleys running south toward Praa Sands; the engine houses sit at the head of each valley where a shaft once dropped vertically into the granite.