The sound mirror at Boulby is 50m west of Boulby Barn Cottage on the north side of the road. It faces due east. It was probably constructed in 1916. The structure is made from reinforced concrete set with corrugated iron shuttering. The sound mirror is a squared U shape in plan and is 17ft high. It survives in good condition although there is some decay to the concrete.
(812 of 824)