NEHL - Sunniside Colliery was a substantial complex close to Tow Law. It was connected to the mainline at Sunniside via waggonway which was disused by the 1890s. There was a number of ground level buildings, as well as a semi-circle reservoir and a number of drifts nearby.

In its final decades it appears the pit was connected by road only, though the pit was dormant after around 1900. Less than half a dozen people maintained the pit by the time it was abandoned in 1925.

It was one of the countless pits owned by Joseph Pease at the end of his life, becoming part of a network which led to him becoming the largest owner of pits of South Durham. At its peak before closure, 312 people worked here.