 The south-east of the parish borders Zeals and Stourhead in Wiltshire, and Bourton in Dorset.In 1991 the parish occupied 523 hectares (1,292 acres).The medieval form of the name was "Penn in Selwood", where "pen" (Brittonic for "head") probably referred to a hill and "Selwood" was the Selwood Forest which once surrounded the area.