The valley is actually a valley of the river Tame, and takes its name from the Holy Well, or Sand Well, which is near its centre. There is evidence of human activity in the valley going back to the Stone Age, between six and eight thousand years ago. There was continuous human habitation around the Sand Well from the 12th century until the early 20th century.

A Benedictine Priory was built close to the Holy Well in 1156, On the site of an earlier Hermitage, and was occupied for several hundred years. The Priory was finally demolished in the sixteenth century. The remains of the Priory, in one form or another, existed until the eighteenth century, when Sandwell Hall was built, though some of the original Priory structure was incorporated.

The Hall was the residence of the Earls of Dartmouth for many years. It passed out of their hands and was demolished in 1928. The area immediately around the Priory and Hall site is designated as a conservation site, and an intensive archaeological survey was carried out between the years 1982 and 1988. Sandwell Park Farm, the home farm for the estate has been extensively restored and opened to the public as a visitor centre, with museum and farm with both rare and common livestock on display.