Founded in the mid-19thC, St. Helena enjoys a prime position in the heart of the Napa Valley, surrounded by wineries and plentifully supplied with up­market restaurants, bed-and-breakfast inns, boutiques and gift shops aimed at the long-distance wine tourist and the week-ending San Franciscan. Most of the activity is along Main Street, illuminated at night by elegant street lamps of 1915 vintage.

Turn-of-the-century mining magnate William Bowers Bourn – who also financed the Californian mansion known to millions as the setting for TV’s Dynasty – was responsible for the landmark stone building which houses St. Helena’s Christian Brothers-Greystone Cellars, which is now a branch of The Culinary Institute of America since 1993. It was once used as a winery.

Close by, the Charles Krug Winery (http://www.charleskrug.com), 2800 Main Street (tel. +1 707 967 2200), has the distinction of being the oldest winery in the valley and the first to crush grapes with a press rather than by foot. The valley’s oldest continuously operating winery, however, is Beringer Vineyards (http://www.beringer.com), 2000 Main Street (tel. +1 707 302 7592), going strong since 1876. The hugely ornate Rhineland-style mansion, which the German émigrés Beringer brothers erected in 1883, is now the winery’s visitors’ centre.

Teetotallers intrigued by wine but otherwise at a loose end in the area might find the Napa Valley Wine Library (https://www.napawinelibrary.com), 1492 Library Lane, a blessing: the continuously expanding stock currently numbers some 6,000 wine-related volumes. Anyone suitably interested can browse at his or her leisure. One visitor to St. Helena who did not have wine on his mind was newly married Scottish writer Robert Louis Stevenson, who passed through the town in 1880 with his bride Fanny Osbourne, on the way to a rustic honeymoon at what is now Robert Louis Stevenson State Park. In an annex of the library, the Silverado Museum celebrates local Stevenson connections with a major horde: manuscripts, first editions, letters, paintings, photographs and much more.

Detour – The Petrified Forest

When Mount St. Helena indulged in one of its periodic eruptions more than 6 million years ago, the tide of volcanic mud and ash which swept through the area uprooted a grove of gigantic coastal redwood trees. As chemicals in the ash reacted with wood fibers, the gigantic trees were turned into stone. To reach the Petrified Forest, as the trees are known, drive five miles west of Calistoga along Petrified Forest Road. Near the entrance, a small museum outlines the extraordinary events which created the fossilized trees, and a short foot-trail explores some of them at close quarters.