|Coflein indicates that there are a confusingly large number of cairns (or possible cairns) on the summit of Twr Pen-cyrn, including the ones below. I think that many of these cairns are one and the same, duplicated and renumbered at different surveys.
Twr Pen Cyrn cairn II/Hen Dy-aderyn cairn (SO20281449)
A centrally disturbed cairn, 16.5m in diameter and 1.9m high, adjoining "Hen Dy-aderyn" (Nprn306262)
Hen Dy-Aderyn (SO20281448)
The tumbled remains of a circular stone structure, 5.0m overall diameter with walls 1.0m thick, have been used as a base for an OS triangulation pillar. Adjoins cairn Nprn306261.
Hen Dy-Aderyn cairn (SO2028814497)
1. A circular foundation with an internal diameter of approximately 3m with walls 1m wide and high. The interior is occupied by a trignometrical pillar. It appears to abut the SW of a cairn and is possibly therefore a later feature. CPAT SMR, 1981
2. A cairn, with a 9m external diameter and 6m internal diameter with a OS Triginometrical point located at its centre. There is a ring of mortared stone, approximately 6m in diameter. The triangulation point is made from cast concrete indicated that is was built at a later date than the mortared stone wall. The stone wall may be the remains of a "Bird House" or game keepers look-out and this is perhaps indicated by the name Hen Dy-Aderyn or Old Bird House.
J. Winterburn, John Winterburn Archaeological Services, July 2005.
Twr Pen Cyrn cairn III (SO20301447)
A cairn about 16.5m in diameter and 1.9m high with a 0.6m deep pit to the south-west of centre. Sited on the summit of Mynydd Pen y Cryn.
Twr Pen Cyrn cairn IV (SO20321445)
A centrally disturbed cairn, 16m in diameter and 1.7m high.
Twr Pen Cyrn cairn VI (SO20311441)
A patch of loose stones 4 m E.-W. by 3 m and 0.3 m high, which may have been a cairn.
Twr Pen Cyrn cairn VII (SO2032714411)
A small, 1.6m diameter cairn on the south facing hill slope to the south of Twr Pen Cyrn.
Twr Pen Cyrn cairn IX (SO2032414470)
Large cairn 13m dia. X 2.5m high. Situated at the highest point of the common. The centre has been hollowed outgiving a space 5m x 0.7 m. Around the edge of the hollow are two shelters, 2.5m dia x 0.5m deep and 3m x 2m deep; two subsidiary cairns 2m dia. X 1m high, both probably modern. On the outside of the cairn against the base is an oval shelter 3m x 2m 0.6m high.
Twr Pen Cyrn cairn XI (SO2029614505)
13m dia. X 2m high cairn, situated on the highest point of the common. The centre has been hollowed out to form a shelter 5m dia x 1m deep.
Posted by thesweetcheat
9th January 2011ce
Edited 9th January 2011ce