The cropmarks of a Roman marching camp at Penrhos were identified in 1969-72 (St Joseph 1973, 237). It is set upon the rounded summit area of an isolated hill. The west side, with a possible entrance, along with parts of the north and east sides have been idendified, defining a subrectangular enclosure, at least 400m NNE-SSW by c.375m, its southern limits are thought to be determined by topographical considerations.

Source: St Joseph 1973 (JRS 63), 214-246.
J.Wiles 20.08.04

A good cropmark was recorded on 23rd June 2003 for the first time since its discovery by Cambridge University.

T. Driver, RCAHMW.