Coed Craig Ruperra comprises 150 acres of broadleaved woodland, conifer plantation, heathland, wildflower meadow and ponds. The woodland still supports a substantial area of coniferous plantation that goes back to the afforestation of the site in the 1920s. The woodland has been designated by Caerphilly County Borough Council as a Site of Importance to Nature Conservation for its status as an ancient woodland site and for its importance to rare and endangered species such as the Hazel Dormouse. The many habitats of the woodland are home to a stunning range of flora and fauna. Many of the species are common but they also include locally and nationally rare species, many of which feature in the Local and UK Biodiversity Action Plans. Included in the flora are several plants considered to be ancient woodland indicators, such as Bluebell, Wood Anemone, Dog’s Mercury, Wild Daffodil, Moschatel, Wood Sorrel and Ramsons.
The woodland lies in a Special Landscape Area and the Scheduled Ancient Monument, an Iron Age hill fort, which surmounts the ridge, and for a long time formed part of the estate of Ruperra Castle, which lies to the south. It has had a long history of occupation and use by man, and as such it has interest both for wildlife enthusiasts and those interested in history.