St-y-Nyll is a large detached house near the village of St. Brides-super-Ely in the Vale of Glamorgan.
It was built in 1924 by the Welsh architect Percy Thomas in the Neo-Georgian style. A Tudor mansion dating from the 1480s had previously stood on the site.[1][2][3] It has been listed Grade II by Cadw since June 1977.[1] It was put up for sale in 2000 for £715,000 and was described as having 13.4 acres (5.4 ha) of grounds.[2] The interior is noted for its plaster cornices, parquet floors, and original fireplaces dating from the 17th century, the Georgian period, and in the style of Robert Adam.[1] It sold for £1.5 million in June 2020.[4]