© Pendle Forest History Group 2017 webfactorynw.co.uk Investigations on the Rigg of England page 1  Spen Brook looking towards Noggarth. Pre medieval Boulder wall located on Noggarth Top above Dimpenley Pre medieval Boulder wall located on Noggarth Top above Dimpenley. Investigations at Spen Brook and Noggarth Top. Report available on request. Pre medieval Boulder wall located on Noggarth Top above Dimpenley