Gloucestershire (/ˈɡlɒstərʃər/ /-ʃɪər/ abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. Gloucestershire borders Herefordshire to the north-west, Worcestershire to the north, Warwickshire to the north-east, Oxfordshire to the east, Wiltshire to the south, Bristol and Somerset to the south-west, and the Welsh county of Monmouthshire to the west.