A small signal box stood on the former Manchester & Milford Railway (nprn 91660) east of the junction with Corporation Siding (nprn 307698) near Ystrad Meurig. At 207 metres (680 feet) above OD, it was at the highest point on the line between Carmarthen and Aberystwyth.
The box is a brick-built structure set short-side to the railway, measuring overall 3.24m north-south by 4.13m; there is a doorway at the east end of the south wall and possibly a small window in the centre of the north wall. The original walls stand to 1.20m above a ground-level plinth on the railway (west) side, higher on the east wall, and further brickwork has been added with a corrugated iron roof to convert the building into a small agricultural shed. Internally there is a fireplace, with an iron rail lintel, against the west wall and another fireplace, less substantial, in the northeast corner. Although Corporation siding was closed and lifted by 1948, the signal box is still depicted and annotated as such on the 1953 Ordnance Survey 6in map (revised 1948).
B.A.Malaws, RCAHMW, 27 September 2013 & 21 January 2017.