Great Western Coffee Shop

At Morwellham Quay, on the Devon side of the Tamar Valley, we sit in a cage-like open carriage on the "mine experience" train, and wait to be delivered underground. In the driver's seat, our guide, Rick, conducts a basic introduction. The George and Charlotte Mine, he tells us, once offered what is known in the trade as a "near-vertical lode", a vein of copper worked by Victorian hard-rock miners in half a mile or so of claustrophobic shafts, eight levels deep. It closed in 1868 and after a few modifications (including the railway tunnel we are about to enter), reopened as a tourist attraction. "Keep your hands, your elbows inside the carriage," instructs Rick before our train rattles into a hole in a cliff. "Watch the drips."

Morwellham Quay is perhaps best known as the setting for the BBC's Edwardian Farm series. And long after filming, it's still a bit like stepping into a scene from Lark Rise to Candleford. Staff wander around in period costume, the occasional horse and cart clatters over cobbles. There are museum displays, recreated mine cottages, a restored Tamar sailing ship called the Garlandstone, the aforementioned farm (technically Victorian) and riverside walks to the copper mine train.

A WELL-MINED HERITAGE

Once the busiest inland port in England, and a shipping hub for some of the world's richest mines, Morwellham is a product of the industrial revolution. A ghost town for most of the past century, its historic collection of stone and slate-hung buildings were rescued from dereliction in the 1970s. Now it's one of the key components of the Tamar Valley and Tavistock district ^ one of 10 areas within the Cornwall and West Devon Mining Landscape, a Unesco world heritage site.

There are other reasons to come here. An area of outstanding natural beauty, it's big on orchards and small-scale farming. Gorge-like cliffs, clothed in forests of conifers and ancient oak woodland, drop down to the banks of the river ^ a slick of glistening mud at low tide. Among reed beds and fields of livestock, rows of white-washed cottages line the steep slopes that roll down the valley from Gunnislake to the boatyards and disused lime kilns of Calstock Quay. It's big on freehouse inns, too: Calstock's Tamar Inn does a mean steak pie, the Rising Sun in Gunnislake has a terrace with peaceful views over the valley, and the rustic Royal Inn at Horsebridge is delightful.

BRANCHING OUT

To get an overview of the area, my husband and I take a Tamar Valley branch line train from Gunnislake to Plymouth and back. On the return journey, the train creeps across country on a single-track railway, through Devonport docks, along the east side of the Tamar's estuary, past the two Tamar bridges, across the river Tavy to the Bere peninsular and into Cornwall. After the thrill of the Calstock viaduct (where the train rumbles over the river on 12 lofty arches of precast concrete, built in 1907), we collect our car from the station and, thereafter, shuttle between Cornwall and Devon across the 16th-century packhorse bridge that crosses the Tamar below Gunnislake.

On the Cornish side, we climb to the top of Kit Hill. At its windy granite summit, 300 metres above sea level, the views are among the best in the county. On a clear day you can see Dartmoor, Bodmin Moor, even Eddystone lighthouse is visible beyond the gleam of Plymouth Sound.

EERIE, OVERGROWN BUT MAGNIFICENT

At Kelly Bray, to the west of Kit Hill country park, we walk through Holmbush wood to find the eerie, overgrown and magnificent ruins of Holmbush Mine. Then we discover the tall, ivy-clad chimney of Clitters Mine hidden in trees on a lane between Gunnislake and Latchley. We spend the night at Old Solomon's Farm (cats, collies, 50 acres and a studio for two in a converted apple store).

On the Devon side of the river, we mooch around Tavistock, a busy little market town which, circa 1850, was completely remodelled by the 7th Duke of Bedford on the profits of his illustrious Tamar Valley copper mines. His presence can still be felt: there is the Bedford ironworks, the Bedford hotel and a statue of the Duke in Bedford Square. In Gulworthy, two miles out of town, we stay at the Horn of Plenty, a former mine captain's house built in the 1860s. Now it's a lovely hotel, with an excellent restaurant and dreamy views over the river, all within a stone's throw of the Tamar Trails network of recreational paths.

We follow part of the trail to what's left of Devon Great Consols. Now little more than rubble and curious hillocks of spoil, it's hard to believe that this was once the richest copper mine in Europe. In fact, it's hard to believe that anywhere on this peaceful river was so intensely industrialised. Morwellham's quays would once have stored enough arsenic to poison mankind. Those miners' cottages are rightly portrayed as pitiful hovels. And in the George and Charlotte copper mine, illuminated tableaux of miners at work depict an arduous life. But when we finally emerge at the other end of the tunnel, what strikes me is the beauty of the place. Aside from a slightly tipsy arsenic chimney rising from a densely forested riverbank, it's utterly unspoilt. Nature has reclaimed this valley. And its rich mix of lost fortunes, mining conservation and fabulous scenery make it a magical place to visit.