The summer house at Garthmaelan is a Grade II listed building situated on a prominent rocky outcrop 200m west of the house. Built of course rubble masonry in the early 19th Century, it is a 'circular, single storey summerhouse set in a planted wood on a rocky knoll' and takes advantage of impressive views towards Foel Cynwch and Foel Offrwm. It measures approximately 3m in internal diameter and has a simple doorway, two window openings (to the north east and north west) and a fireplace.
Sources: CADW listed building database, reference number 5136. Notes written to accompany photographs by Paul Davis in November 2019.
RCAHMW, 18th February 2020