Bigsweir Woods (grid reference SO546060) is a 48.16-hectare (119.0-acre) biological Site of Special Scientific Interest in Gloucestershire, notified in 1984.

[3] The site is within the Wye Valley Area of Outstanding Natural Beauty and is part owned by the Woodland Trust.

[1] Wye Valley Woodlands/ Coetiroedd Dyffryn Gwy are recognised as a Special Area of Conservation (SAC) under the EU Habitats Directive.

The wood is dominated by Sessile Oak but includes some Beech, Small-leaved Lime and Birch.

[1] Local herbs include Forester's Woodrush (Luzula forsteri), Bitter Vetch, Alder Buckthorn and Wood Fescue (Festuca altissima).