Like nearby Rutherford, the village of Oakville sits in a section of the valley where climate and soils are ideally suited to grape production. Consequently both tiny vil­lages are completely dominated by more wineries than even seasoned oenologists can shake a stick at.

The 45-minute tours and tastings offered by the Robert Mondavi Winery (http://www.robertmondaviwinery.com), 7801 St. Helena Highway (tel. +1 707 226 1395) are unrivalled for revealing what California wines and wine-making are all about, and should be the first stop in the Napa Valley for the wine novice. The winery’s mission-style buildings also feature a gallery displaying Californian artists’ work. In summer, the strains of live classical music percolate through the expansive gardens while Silver Oak Cellars (https://www.silveroak.com), 915 Oakville Cross Road (tel. 707 942 7022), occupies a former dairy and devotes itself to producing Cabernet Sauvignon – to a high standard.

Sauvignon Blanc is the speciality of the small Robert Pepi Winery (http://www.pepi.com), 7585 St. Helena Highway. 

Detour – Old Faithful Geyser

One manifestation of the geothermal activity around Calistoga is the Old Faithful Geyser, a mile north of the town, which has been sending a high-pressure jet of boiling water 60 feet skywards every 30 or 50 minutes (depending on local seismic activity) for many years. A small visitor centre explains the fascinating process, although for anyone who has seen geysers elsewhere in the world, the admission fee will seem excessive.Robert