Horizontal Section No. 44 (1858). 1. Across Denbighshire Coalfield, through Bwlch Gwyn, Brymbo, Holt and Peckforton Hills. 2. Through Tan-y-Castell, Wynnstay Ho. and Overton. Geological Survey of GB. 2ndHorizontal Section No. 44 (1858). 1. Across the Denbighshire Coalfield, through Bwlch Gwyn and Brymbo, Holt and the Peckforton Hills. 2. Through Tan y Castell, Wynnstay House and Overton, across the Denbighshire Coalfield. Geological Survey of GB. 2nd edition. Located on Old Series one inch maps 73nw & 74ne. Hand coloured engraving, 71 x 101. 5cm, 1: 10,560 scale (6= 1mile). Flat, linen taped edges, very age toned top margin. Library stamp on back,