Summerhouse, about 120 metres south of Montacute House, and the row of 5 freestanding columns to east

The summerhouse, located about 120 metres south of Montacute House, dates back to 1588 but is now mostly from the 20th century. It is constructed from Ham stone ashlar and features a bitumen felted lean-to roof behind a parapet. This single-storey structure has three bays and faces north along the Cedar Lawn. It has a stepped base, moulded plinths, a frieze and cornice adorned with triglyphs and panelled metopes, and an open balustrade with obelisk finials. The central bay includes a false Dutch gable with a coat of arms and an incised date. The facade features an arcade of three semi-circular arches with lozenge rustication. Inside, there is a panelled dado with shell-hood niches in the east and west walls, and a plain flat ceiling.

Starting 5 metres east of the summerhouse, there is a row of five plain Tuscan columns on plinths, which serve as landscaping features. The area known as Cedar Lawn was previously called 'Pig's Wheatle Orchard' and was likely converted into a formal garden in the mid-19th century. The summerhouse's 16th-century style facade may actually date from Lord Curzon's tenancy in the early 20th century.