Excavators identified five furnaces, historic bottle glass, brick floors, a stone staircase and a 22-metre tunnel in the southern part of the development site. A post-excavation report prepared by Archaeological Services Durham University said the surviving remains revealed at least three phases in the operation of the glassworks. Well-preserved brick floors and walls in the northern rooms of the 18th-century glassworks (Image: Archaeological Services Durham University)Large quantities of bottle glass were recovered, including early-to-mid-18th-century forms and evidence of both free-blowing and mould-blowing techniques. Documentary and map evidence showed that an 1815 plan of Whitehaven marked an 'Old Glass House' in the southern part of the site. A drone image showing the scale of the excavations (Image: Archaeological Services Durham University)The pottery had been established by 1830.