Allt Rhongyr is within the Brecon Beacons National Park, adjacent to Craig y Rhiwarth Nature Reserve and offers dramatic views of the Tawe Valley. It features a diverse mix of limestone grassland, acidic grassland and woodland and it was once the site of an iron age hillfort. The site is now managed by grazing under an agri-environment scheme.
The Pen y Waun nature reserve consists of two small fields situated on the edge of Waun-y-Mynach common. The fields were former garden plots for nearby cottages.
This nature reserve used to be part of the railway line from Brecon to Hereford. Parts of the railway were built along the line of the earlier 1818 Brecon to Eardisley horse-drawn tramroad that carried coal and wool. The railway company opened the line for steam in 1864. In 1962 the line closed and in 1970 it became a nature reserve.