This site on MAGIC is described as Knapperthaw Stone Circle.
Unfortunately the SMR summary is currently not available online.
In his book 'Walks in Ancient Lakeland', Robert Harris describes this site as "the remains of a cairn and a strange ringed enclosure". He also describes a "large block inside the ring which has two cup marks carved into its flat upper surface".
Walks in Ancient Lakeland
Pub Sigma Leisure 2001