Hemel Hempstead (/ ˈ h ɛ m əl ˈ h ɛ m p s t ɪ d /) is a town in the Dacorum district in Hertfordshire, England, 24 miles (39 km) north-west of London, which is part of the Greater London Urban Area. . Albans. Hemel Hempstead (/ ˈ h ɛ m əl ˈ h ɛ m p s t ɪ d /) is a town in the Dacorum district in Hertfordshire, England, 24 miles (39 km) north-west of London, which is part of the Greater London Urban Area.