Ice House, Hillsborough Castle, The Square, Hillsborough, County Down, BT26 6AG

Ice House, Hillsborough Castle

A free-standing grotto-like mound erected around 1780 in the grounds of Hillsborough Castle, containing a redbrick vaulted ice house set mostly below ground level. The structure was restored in 1996.

The mound is planted naturally in ferns and features a voissoired boulder arched opening to the north. This opening leads to an oval-shaped double-vaulted redbrick chamber accessed via a short brick-lined passageway with flagstones and a timber lintel. The chamber is now secured with a modern steel gate. The roof is constructed of boulders and redbrick.

The ice house is shown, captioned, on an estate map of around 1800 and does not appear on earlier maps, confirming its late eighteenth-century date. It deliberately imitates the ornamental effect of a grotto, a fashionable garden feature that had developed from Italian Renaissance prototypes in the sixteenth century and spread through Europe, arriving in Britain with Alexander Pope's famous grotto at Twickenham in the early eighteenth century. Early Irish examples were designed by Edward Lovett Pearce at Stillorgan and by Mary Delaney at the Bishop of Killala's seat in County Mayo, also in the early eighteenth century. The Hillsborough example is a particularly fine instance of an ice house deliberately designed as a visual garden feature, using rustic stonework at the entrance and positioned on a hill above an artificial waterfall, where it resembles a moss and fern-covered rockery.

Ice houses were constructed throughout the eighteenth and nineteenth centuries but are now rare, with only nine known to survive intact in Northern Ireland. Most fell out of use in the last quarter of the nineteenth century when commercial ice production became viable. The Hillsborough ice house is shown uncaptioned on the first edition Ordnance Survey map of 1833 and captioned "Ice Ho[use]" from the second edition of 1858 onwards.

The structure sits within the landscaped grounds of Hillsborough Castle, with a rockery and waterfall to the west. It has group value with the other listed structures at the castle and represents an increasingly rare demesne feature of considerable technical and historical interest.