Shell Houses and Grottoes

In the eighteenth century no fashionable estate was considered complete without an artificial grotto. Wealthy men and women spent fortunes and many years, sometimes decades, creating them. Yet an imitation cave, even one lined with shells, seems an unpromising way to enhance a damp English park. When and where did the craze start?

The earliest grottoes were shrines built over sacred springs in ancient Greece. Over time these evolved into temples and were popular in ancient Rome, where the term nymphaeum was used for both formal temples dedicated to water deities and artificial grottoes surrounding public fountains. Smaller grottoes were also popular additions to Roman villas and gardens, decorated with shells and a maritime theme. Architects in Renaissance Italy revived the grottoes of ancient Rome to lend an air of historical authenticity to their neo-classical villas and gardens and these caught the public imagination and swept across Europe. In the early 1600s the popularity of the artificial grotto reached Britain.

The first British grottoes were built as indoor rooms, often in the area below the stairs leading to the first-floor reception rooms, or piano nobile, in a neo-classical villa. The porch area under the entrance staircase at Osterley House in West London is still referred to as the grotto, although it is now undecorated. In 1624 James I had a shell grotto in his drinking den in the undercroft of the Banqueting House in Whitehall. In 1626 an open-air shell room was installed at Woburn Abbey, Bedfordshire, and another shell room in Skipton Castle in Yorkshire in 1627, both designed by Isaac de Caus. Nearly all the grottoes of the early seventeenth century were swept away by the English Civil War in the middle of the century and the only surviving examples today are the shell rooms at Woburn Abbey and Skipton Castle.

It was not until the eighteenth century, when a period of peace and prosperity enabled the British to travel freely on the continent, that interest in Renaissance architecture and garden design revived. In 1710 the 1st Earl of Halifax built the Baroque water gardens at Upper Lodge in Bushy Park, opposite Hampton Court Palace. These included a water cascade with side alcoves containing painted backdrops, to resemble a grotto, changed seasonally. The water cascade was extensively restored recently and is now open to the public - although without the painted panels in the alcoves.

The eighteenth century was the age of the Grand Tour, when wealthy young men travelled to Italy and returned home, fired up to recreate on their own estates the Renaissance wonders admired in Europe. Among the ‘must-have’ items, the artificial grotto took pride of place. In landscaped parks across the country a grotto would often be the highlight of a tour of the grounds. Many neo-classical mansions had shell rooms. Two main grotto styles were popular: the nymphaeum, simulating a small classical temple, and the shell grotto, a shell-lined artificial cave or rustic pavilion; often grottoes fused elements of both styles Water was a popular element and many grottoes were built on or near water.

Two early eighteenth-century grottoes which survive today are in Carshalton in the LB of Sutton. Now a ruined hulk, the huge artificial grotto in Carshalton Park was built in 1720s, by the Italian architect Giacomo Leoni, for Thomas Scawen. A series of vaulted chambers, surmounted by a statue of Neptune, were lined with shells, while the grotto was built over springs from the river Wandle that fed a canal in front of it. Now a decaying graffiti-ised relic, it must have been magnificent in its heyday. A nearby rival grotto, in the grounds of Carshalton House, also dating from the early 1720s, has fared better. It was commissioned by Sir John Fellowes, a financier, and managing director of the notorious South Sea Company, who employed Charles Bridgeman to landscape his grounds. Known as the Hermitage, it is a one-storey building of ashlar stone, plainly ornamented but notable for its echo chamber.

In 1725 the poet Alexander Pope (1688-1744) built a celebrated and influential grotto in the tunnel linking his house and garden next to the Thames in Twickenham. It was decorated with shells. glass and mirror shards and led to a shell temple. The house and shell temple have long since gone but the tunnel has survived, although much changed by Pope himself over the years from its original appearance.

In the mid-eighteenth century, Rococo style, inspired by the swirling patterns of shells, was applied to design everywhere. Now the shell grotto really came into its own. Shells were avidly collected and purchased in large quantities to decorate grottoes. At Hampton Court House on the edge of Bushy Park, Thomas Wright designed a house and a Rococo garden containing a rustic shell pavilion (built in 1767) for the 2nd Earl of Halifax to share with his mistress, the actress Mrs Anna-Maria Donaldson. The grotto was restored in 1986 by Diana Reynell. There is another surviving shell grotto at Southside House in Wimbledon.

There is a subterranean grotto in the grounds of Marble Hill Park in Twickenham, built for the Countess of Suffolk (1688-1767) when the grounds were laid out by Charles Bridgeman with advice from Alexander Pope. This grotto had a new entrance built in the mid-1980s and at that time the shells and minerals found in it were transferred to Marble Hill's basement for safekeeping. A delightful small shell grotto also survives in the grounds of Thames Eyot, a block of 1930s flats in Twickenham, a relic of an earlier house on the site. Used as a shed, it has recently been under threat of demolition.

The fashionable gentleman who could not spare the time to design his own grotto could hire Mr Castles of Grotto Passage in Marylebone to build one for him. Today a narrow thoroughfare, in the 1750s this was the location of Mr Castles' yard and grotto showroom, on a one-acre site on the edge of London. The public flocked to visit the shellwork displayed there. Mr Castles made his name with a grotto for Sir Robert Walpole at the Royal Hospital Chelsea. This is not known to have survived; however recent sale particulars for the listed Gordon House, in the grounds there, refer, tantalisingly to a listed grotto.

A grotto boathouse was built at Wanstead Park (now in the LB of Redbridge) by John, 2nd Early TyIney in 1764. This had a shell- decorated room above the boathouse where the Earl stored his collection of coffins. It survived the demolition of the house only to burn down in 1884. Today the façade remains as a haunting ruin overlooking the lake.

At the height of the grotto's popularity, grotto-esque features were used to enhance many other structures. There is a grotto cascade in Chiswick House grounds and Valentine's Park in LB Redbridge has a grotto-esque alcove seat and a grotto bridge, all recently restored. There is even an eighteenth century grotto seat, now used as a bus- stop, in Esher. Grottoes also moved into the public realm when grotto features were built to enhance public pleasure gardens like Finch's Grotto Gardens in Southwark in the 1760s.

From the middle of the eighteenth century, a more natural style of grotto became popular. The shells and minerals which had lined earlier grottoes were moved into natural history collections and the grotto evolved into a simulated limestone cave. Pope had already remodelled his Twickenham grotto before his death to more closely resemble a natural cave, and there is a wonderful limestone grotto cave, restored by Diana Reynell, in Painshill Park in Surrey.

As the nineteenth century arrived, new developments in gardening led to the popularity of conservatories and massed bedding schemes, and the shell-decorated grotto was replaced by large rockeries and simulated caves made from natural rocks and Pulhamite (artificial stone). Its influence lingered on in the grotto arches and water features which were popular in municipal parks in the late nineteenth and early twentieth centuries. Even today, over two centuries later, over two hundred grottoes, in varying states of repair, have survived and can be visited around the UK with many more waiting to be discovered.