OAN field survey, located by GPS to an accuracy of +/- 1m. Site of Frozen Clock located on the current OS mapping. The site is a ruined water clock located on the east end of the estate land at Bryn-Adda flats, just to the north of Tyddyn-Uchaf limekiln. It consisted of a two celled L-shaped building with the longest side running east-west for 12m and a smaller cell on the north west side. The construction is of well coursed, smooth, square-cut medium-large sandstone blocks. The walls are in a ruinous state and survive up to a maximum of six courses high (1.5m) on the west end, all the rest only survives up to three courses high, but the internal walls are too overgrown distinguish. The building is placed on an earthen platform which is about 17m long east-west by 9m wide north-south and an earthen bank butts up against the western gable end. The building is located 10m to the south of a stream that has a small stone crossing point. 2002/06/13/OAN/PJS