Am dan y warchodfa

Several broad tracks which date from earlier coal extraction, including the route of a former tramway, run through the reserve. The site is underlain by Pennant sandstone, and a number of small coal seams outcrop within the reserve. A sandstone cliff about 8 metres high, and over a kilometre long, runs through the reserve at the top of the slope, offering fine views over Alltwen.

The woodland has a diverse age structure particularly in the western part of the wood. A few dense areas near the entrance reflect where clear felling has occurred in the recent past. The woodland canopy comprises of a mosaic made up of Sessile Oak, Beech, Birch, Ash, Sycamore, and Alder. Part of the reserve is shown as not wooded on a map dated 1831.

In most of the western, more ancient part of the woodland, there is a prominent shrub layer where Hazel and Holly are particularly abundant. Several minor watercourses descend the slope and there are areas of impeded drainage at the base of the slope where Alder grows and large areas of Marsh Violet and Yellow Pimpernel can be found.

The reserve being rather damp supports a variety of lower plants including mosses and liverworts.