The Grotto

Grottoes have been added to buildings and gardens to provide places for contemplation, recreation and social activity from the Renaissance onwards. The earliest grottoes in England date from the 1620s and were chiefly located inside the house, but later grottos were either free-standing or, like the Marlborough grotto, could take the form of caves cut into a hillslope. In the early eighteenth century there was a shift of emphasis to ‘follow Nature’ and bring forth the ‘genius of the place’. They were already ornamented with shells, and in the early eighteenth century, flint and iron ore were interspersed with fragments of mirror to provide glittering effects.

Frances, Countess of Hertford (1699-1754) belonged to that group of ‘poetical ladies’ whom Joseph Addison would have had in mind when recommending they decorate small shell grottoes as an amusing alternative to needlework. Frances was a strong supporter of budding mainstream poets like James Thomson and Stephen Duck, and grottoes were widely imagined as a haunt of the Muses. We do not know precisely when the grotto was built. The poet Stephen Duck, who benefited from the Countess’ patronage, hinted that it may still have been in the process of being worked on in the late 1730s when he wrote, in his poem ‘A Description of a Journey to Marlborough’,

Within the Basis of the Verdant Hill
A beauteous Grot confesses Hertford’s skill;
Who, with her lovely Nymphs, adorns the Place;
Give ev’ry polish’d stone its proper Grace;
Now varies rustic Moss about the Cell;
Now fits the Shining Pearl, or purple Shell.

Presumably its decoration was complete by 1739, as in a letter written in June that year Lady Hertford mentioned it, saying ‘The grotto which we have made under the mound … without partiality I think is in itself much prettier than that at Twickenham.’ This is a reference to the famous grotto belonging to the poet Alexander Pope, which Lady Hertford clearly had in mind when the Marlborough grotto was designed. It is much smaller than Pope’s, but the shellwork is much more decorative. Newly restored, it now ranks among the finest examples of its kind. As with Pope’s own grotto, we should expect construction and other works to have taken place over a period of time, with additions made here and there in accordance with changing enthusiasm and as different interests evolved.

After the Hertfords left Marlborough, they bought a new estate at Richings, near Windsor, which had belonged to Lord Bathurst, who had corresponded extensively with Pope on gardening matters. Here Lady Hertford created another grotto, surmounted by a ruined arch. She found another poet to write about it, though less effusively than Stephen Duck:

Within, an ample concave swells
Of Pummice wrought, and shining shells;
Where , near a Seat of native stone,
A Fountain keeps its bubbling Moan,
And from beneath the craggy Wall
Creeps slow, with tinkling –trilling– Fall.

For many years, the grotto was neglected: it was used variously to store vegetables and as a bicycle shed. In 1980, Diana Reynell, a former teacher at Marlborough College, and Simon Verity, a distinguished letter-cutter, began a ten year programme of restoration, much of which had to be reimagined. Remains of a circular basin lined with slag and shells were discovered at the foot of the rear wall of the main room. It has been re- stored together with the niche above, where the broad band of rich shell- work surrounds a modern stone urn carved by Simon Verity after an eighteenth-century original at Petworth House, West Sussex. The vessel is placed in such a way that water can divide around it and fall onto the open half of a giant clam (Tridacna gigas). This large shell is another modern introduction, acquired through ‘begging’ at the food hall of Har- rods in London,where it was being used in a display. The modern recon- struction of the grotto seeks to remain true to the spirit of the original and conveys a good sense of what it may have been like.

The walls, alcoves and ceilings of the three rooms inside with their alcoves or recesses,together with the vaulted ceilings, were originally cov- ered with a variety of shells, pieces of rough stone and iron slag, through which white ‘snail trail’ patterns of baked flint meandered in an apparently random manner. Patches of surviving shellwork and cladding, together with rusted iron cramps that were used to hold the heavier materials in place, were recorded. As in other contemporary grottoes they included both freshwater and sea shells from the Mediterranean and British shores and rivers, as well as exotic specimens from the West Indies

The current major restoration plan for the Mound has been completed in 2023 with new work on the grotto. This has involved removal of a very large yew tree whose roots were growing into the back of the grotto, the reconstruction of the roof and the installation of a sedum surface, all of which were done in 2015. The masonry has been extensively repaired, and the frost protection wrapping was removed this month. The interior has been thoroughly cleaned, and loose and missing shells have been replaced; in some areas, however, there is no base left, and these spaces are deliberately blank. One important feature, the blue slag produced by eighteenth century steel making, has been unobtainable, but the overall effect of the repairs and cleaning have revived the interior dramatically. The reflections from the mother of pearl in the shells, the glass fragments in the roof and the metallic elements, now bring it to life. At night, with special low level spotlights, it is particularly dramatic seen through the closed ironwork gates.