The parish of Holwell lies north of Hitchin, west of the A600 to Bedford. Holwell is the only settlement in the parish.
Holwell Parish Council’s website contains useful information about the village.
Holwell’s entries in Domesday Book; the first entry is for Cadwell, now in Ickleford parish, and the second is for Holwell proper. Both places were in Bedfordshire until 1894, when they were transferred to Hertfordshire.