On the eastern edge of Radnorshire, just off the busy A44 main road, is a dolerite and gabbro rock outcrop that has retained an assemblage of rare plants since the late glacial period. Despite covering an area of just five hectares, Stanner Rocks National Nature Reserve is one of the most important botanical sites in Wales.
Created by volcanic activity during the Precambrian era, more than 600 million years ago, Stanner Rocks supports some of the oldest rocks in Wales and is of national importance on account of its geology alone. It is this special geology that has allowed a rich assemblage of plants to develop on Stanner’s steep south-facing cliffs.