The other feature of the Mound that has attracted visitors, particularly in the eighteenth century, is the Grotto. Grottoes first appeared in English houses and gardens in the sixteenth century. By the time that the Marlborough garden was created, the accepted style was a cave, preferably set in a wilderness, and on occasions provided with a resident hermit, though many hermits quickly repented of their new occupation. The most famous of these constructions, completed in 1725, was that of Alexander Pope at Twickenham, where it became a place for his own contemplation and writing. The vogue for grottoes was such that Joseph Addison, founder of The Spectator Magazine, wrote in 1714 that ‘there is a very particular kind of work, which seems very well adapted to a poetical genius: it is the making of grottoes. I know a lady who has a very beautiful one, composed by herself; nor is there one shell in it not stuck up be her own hands.’
Lady Hertford wrote poetry herself, and was also patron of poets, including the local celebrity, Stephen Duck. Describing the Mound in 1736, he wrote
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.
Lady Hertford herself declared that her grotto ‘is much prettier than that at Twickenham’.
The grotto suffered from the same gradual decline as the rest of the gardens at Marlborough, and by the 1970s had been used variously as a vegetable store and a bicycle shed, as well as for illicit smoking by boys from the College. Diana Reynell, who had taught at the school, proposed a plan for its restoration, which she and her helpers carried out between 1980 and 1986, with the help of the sculptor and letter-cutter Simon Verity. The centrepiece of the grotto is now a vase carved by him, above a giant clam shell, ‘begged’ by Diana Reynell from Harrods in London, where it had adorned the food hall.
Diana Reynell was a pioneer in the restoration of shell grottos, and thirty years later her work in turn needed repair and restoration. This was completed in the spring of 2023 by Sally Strachey Historic Conservation, using expertise learnt from restoring similar grottoes elsewhere.