At the western extremity of the Lleyn Peninsula, on Mynydd Mawr, there are extensive remains of a World War 2 signal station, including an access road and paths. The site is approached by a metalled track and a purpose-built concrete road some 620m long, bounded by kerbs and provided with passing places. Adjacent to the lower end of the road is the concrete base of a building (SH 14220 25720), presumably once a gatehouse to control access. The upper end of the road terminates in a triangular turning area and beyond are two single-storey standing buildings, each with a flat roof, protected by a curving stone wall to the west and north, and the concrete bases of at least two further buildings. The more westerly of the two standing buildings (SH 13953 25861) was latterly used as a coastguard lookout until 1990 and the other is believed to have housed an electric generator. To the south west is a grooved concrete path and steps, some 210m long, which passes the concrete base of a further building and leads down to a levelled area (SH 13820 25730) upon which are the concrete bases of probably six buildings and other structures.
B.A.Malaws, RCAHMW, 28 July 2009.