An underground spa has opened, 40ft (12.1m) below the southern end of The Meritage Resort within the Napa Valley in California, US.

The 9,000sq ft (836sq m) spa has been designed as an ‘underground oasis’ within the famous wine region and cost US$7.5m (5.6m euro, £3.8m) to build.

Situated beneath the grape-crusher statue at the Meritage, Spa Terra features 10 private, temperature-controlled treatment rooms, separate male and female steam saunas and soaking pools with water walls.

The spa will have a complete menu of treatments with a wine service available. Design features include heated tiles and vaulted ceilings with hand-wrought fixtures throughout.

The spa’s architecture mirrors the Mediterranean theme of the 158-bedroom Meritage Resort and its neighbouring Vino Bella Resort, which are located side-by-side on an eight-acre private vineyard.

Spa architect David Bury said: “The cave environment is incredibly well-suited to spa design for a number of reasons. It maintains a constant temperature, which makes it very energy efficient, it’s quiet and, structurally, it’s incredibly stable. Perhaps most exciting for us, we were able to focus all our energy on interior elements, since the exterior of the project was handled by Mother Nature.”