The crossword solution for the term 'Hertfordshire Neighbor' is Essex, which is a county in the East of England. It borders Hertfordshire to the west and has a population of over 1.4 million people. Essex is known for its coastline, which includes the Thames Estuary and the resorts of Southend-on-Sea and Clacton-on-Sea. It is also home to some of the oldest recorded settlements in Britain, including Colchester, the oldest recorded town in Britain.