Summerhouse and Underground Vaulted Chamber in grounds of Rookwood Hospital

External walling faced with Bath stone ashlar, now extensively damaged, rubble and brick internally. Octagonal single storey ''Gothick'' style structure in the manner of Batty Langley which is set on an earthen mound. Each bay with buttress and narrow pointed window opening with hoodmould, the sash windows are now (April 2002) gone and several of the openings blocked with concrete blocks. In the south facet a square headed doorway with damaged clustered columns above a short flight of steps. Lunette above with trefoils. Machicolated parapet with battlements. formerly the parapet had a crocketted pinnacle at each angle of structure, all are now gone. At base of mound to the rear, a flight of stone steps leads down to a contemporary vaulted chamber beneath the summerhouse.

The interior of the chamber, possibly intended for an icehouse (note that the door is on the north side) has a brick vault and walls of stone rubble. It was not entered at resurvey.