Dewstow House

Dewstow House, Caldicot, Monmouthshire, Wales, is an earlier nineteenth century villa in a Neoclassical style. The house is notable as the site of "one of the strangest gardens in Wales." The building itself is plain; described by architectural writer John Newman as a "simple three-bay villa", it has extensive views over the Severn Estuary. It is a Grade II listed building.

Within, and under, the grounds lies a "network of very rare and unusual underground gardens" constructed in the late nineteenth and early twentieth centuries. Comprising "underground passages and top-light chambers with artificial rock-work and stalactities," the garden structures have three separate Grade II* listings as a result of their importance. The gardens were rediscovered, excavated and restored at the beginning of the twenty first century and are now open to the public.