The Templetown Mausoleum, located in a graveyard adjacent to Castle Upton, County Antrim, dates from 1789. Both the house and the mausoleum were designed by Robert Adam. Customarily the commission for this monument is attributed to Arthur Upton, Baron (and future Viscount) Templetown. However, a plaque above the entrance notes that it is ‘Sacred to the Memory of the Right Honourable Arthur Upton’, who was Lord Templetown’s uncle and who had died in 1763, so it may be that Adam’s client was Lord Templetown’s father (also brother of the deceased Arthur). In any case, the rectangular mausoleum has a facade taking the form of a triumphal arch with rusticated breakfront. On either side are niches holding classical urns (a third tops the building) and above these circular reliefs of Coade stone featuring classical figures in mourning. Inside, the mausoleum is entirely empty other than a series of plaques on two side walls commemorating various members of the Upton family. Castle Upton itself was remodelled in the 19th century with the loss of its original Adam interiors, so this mausoleum represents a rare surviving example of the architect’s work in Ireland.