Seaweed, Smugglers & Spa Pools

By Helen Butcher

John Stackhouse

Near tiny Prussia Cove in the depths of Cornwall, in South West England, lies a secret 18th-century Georgian bathroom hidden deep in the Cornish Cliffs. It was built at the end of the 1700’s for botanist John Stackhouse’s wife, Susannah Acton, to bathe by the sea in complete privacy. 

During this time sea bathing was highly fashionable with the aristocracy. Seaside resorts like Brighton provided a thriving service, with bathing machines for ladies and gentlemen to enjoy. Saltwater was also cited to cure a wide range of ailments—drinking it as well as bathing in it.

Stackhouse, Oxford-educated and a marine biologist long before the term was invented, had an interest in the analysis and categorization of seaweeds and marine algae. He was particularly interested in the propagation of algae from their spores, and this particular stretch of slate shoreline provided some of the rarest specimens and plentiful opportunities for his research. Having lived previously in the famous spa town of Bath, it seems he was keen for his new wife to appreciate the health benefits of cold-water bathing.

His home, Acton Castle, named after Susannah, was built in 1775—a striking castellated granite mansion on the cliffs above the coves, overlooking the expanse of Mounts Bay. Stackhouse commissioned the architect John Wood the Younger, straight from designing The Royal Crescent in Bath, to build a gentleman’s retreat where he could carry out his botanical studies. The remains of his seaweed storage tanks can still be found in the gardens today, which he filled with seawater apparently pumped from the cove below.

The Carter Brothers

A tenant on Stackhouse’s land and employed as key holder and caretaker of Acton Castle was the notorious John Carter, Cornwall’s most famous real-life smuggler. Known as the “King of Prussia” due to his resemblance to Frederick the Great, the Prussian monarch, he and his brothers Harry and Charles, ran an efficient and profitable smuggling operation centered around three sheltered and secluded local inlets, Piskies Cove, Bessie’s Cove, and Porthleah—later renamed Prussia Cove. They owned two fast sailing ships—a 19-gun cutter and a 20-gun lugger, each with a smaller boat for inshore work and a crew of around 30 men. Between 1777 and 1807, Carter was the most successful smuggler in the district.

A busy trade in wine, spirits, tobacco and tea from across the channel in Brittany ensued, when official taxes were at an all-time high to fund the wars in France. Despite his profession, John Carter was a devout Methodist, well-liked and known for his honest dealing. He was regarded as an upstanding member of the community—swearing and unseemly behavior was banned on his ships and quayside sermons were held for the ships’ crews. Many people in Cornwall felt that the high taxes were unfair and saw nothing wrong with the smuggling of such desirable items. It was seen as resourceful and enterprising, rather than criminal, and the local residents could be relied upon not to give the authorities any information on the Carters’ activities.

It is thought that John Carter and his men—highly skilled in tunneling—built the spa pool for Stackhouse, along with lots of other secret passages, harbors and slipways locally. Old Cornish tales talk of tunnels that lead from Acton Castle and other nearby properties to the coast, but these have never been found.

John Carter disappeared and was presumed dead in 1807, although other members of the Carter family are said to have continued the family business. Harry retired to a nearby farm and spent his final years as a neighborhood preacher. Most smugglers would have been illiterate but Harry, known as Captain Harry, had taught himself to read and write and in 1809 recorded his memoirs in a book published as The Autobiography of a Cornish Smuggler. By 1825, Coastguard Cottages were built above the coves to put an end to the smuggling.

The Spa Pool

On a sunny calm day, armed with torches (flashlights), cameras, and sensible footwear, we set off along the cliff path to hunt for this secret piece of local history. Stackhouse Cove is certainly secluded, with no roads leading to it. Your choices are a 20-minute coastal path from either Perranuthnoe Village to the right or Prussia Cove to the left. Access is a steep track down through overgrown brambles and then a clamber over the rocks which make up most of the beach. A strip of shingle runs along the top, backed by high crumbling cliffs full of caves.

Halfway along we spotted the slit in the cliffs above us, and we scrambled up to it over the slippery rocks. Originally there had been steps cut into the rock, leading up to the entrance. Today, all except the top step had long since worn away. We had found the entrance—although it could easily be mistaken for a mine adit, which are a common due to Cornwall’s tin mining history.

Four meters (about 13 feet) back into the cliff face of solid rock, the narrow tunnel opened to reveal a chamber around eight feet long by six feet high. It was almost total darkness, with only glimpses of light provided by the entrance tunnel and a chimney-type hole in the roof above us. The rectangular rock cut bath was central and surrounded by a ledge, although not enough room to get changed for your dip. Modesty dictated that Susannah, unless particularly liberated for the time, would probably have had to bathe fully clothed.

The pool was filled by a constant drip of icy cold spring water from a nearby stream, which fell through a hole high in the cave. The water was an uninviting murky green and the cave was full of scuttling creatures (I’m sure I saw a cockroach) but in the interest of research and to satisfy my curiosity, I climbed in. It was about three feet deep to the solid rock bottom with the constant overflow of water cleverly draining out along the approach tunnel.

Another pool, open to the air and filled by the tide, can be found at the far end of the beach. It is revealed at low tide, perfect for when Lady Acton wanted to bathe with a view. And perhaps with a warming glass of smuggled brandy!

Learn more about the best beaches and destinations for sea and beach glass, seashells, fossils, rocks, and more beach finds around the world. Articles ›

This article appeared in the Beachcombing Magazine January/February 2022 issue.