"At Castleruddery, the mind goes into an overdrive of attempted understanding. What is this large and peculiar thirty-metre-diameter earth circle with its chaos of uprights, boulders and two enormous entrance 'recumbent' portals of white quartz? The slovenly earthbank is reminiscent of those famous unditched henges at Mayburgh, Cumbria, and the Lios, in County Limerick. The inside of this earthbank is lined with so many stones, both standing and formerly standing, that it is in places almost contiguous. What was its finishing like before erosion took place. Castleruddery has suffered so many depradations that most contemorary monuments would by now be unrecognisable were they to be left in a similar state. At the entrance to the monument, two white quartz stones of three and two-and-three-quarter metres in length create a defined and tight Lios-type entranceway. They have been estimated to weigh at least fifteen tons.
Work done at Castleruddery in the 1970s and 1980s has shown that the monument was a very involved creation. The main earthbank was originally taken from a long silted up ditch around twenty-four feet outside the circle. Outside this ditch was another earthbank held in place by timber posts, whose postholes have shown up in a resistivity survey. Visitors to this site may be frustrated by its very strange appearance, but, considering its involved construction history, Castleruddery is still in remarkably fine shape." - Julian Cope, The Megalithic European.