Hertfordshire

            Hertfordshire, administrative and historic county of southern England, adjoining Greater London to the south. The administrative county and the historic county cover slightly different areas. The administrative county comprises 10 districts: East Hertfordshire, North Hertfordshire, Three Rivers, and Welwyn Hatfield; the boroughs of Broxbourne, Dacorum, Hertsmere, Stevenage, and Watford; and the city of St. Albans. The Potters Bar area in Hertsmere borough lies outside the historic county of Hertfordshire and within the historic county of Middlesex..