2 Best Sights in Capri, Ischia, and Procida, Italy

For the ultimate Ischian spa escape, try the stylishly landscaped park of Giardini Negombo. Designed around a beach of the finest sand, by the scenic Bay of San Montano, it was created decades ago by Duke Luigi Camerini, a passionate botanist (who named his resort in honor of its resemblance to a bay in Sri Lanka). There are 12 saltwater or thermal pools here, plus facilities for hydromassage, a beauty center with sauna and Turkish bath, sports facilities for diving and windsurfing, a bar, restaurant, and, according to the brochure, "a boutique for irresponsible purchases." All this is set in gardens with 500 species of Mediterranean plants and several panoramic views. Everything here—modern stone waterfalls, elegant poolside tables with thatched-leaf umbrellas, sensitive landscaping—is in the finest taste. At night, the outdoor arena often hosts big-name concerts. The Hotel della Baia ($$) is also on-site.

The largest spa on the island has the added boon of a natural sauna hollowed out of the rocks. Here you can sit like a Roman senator on stone chairs recessed in the rock and let the hot water cascade over you. With countless thermally regulated pools, promenades, and steam pools, plus lots of kitschy toga-clad statues of the Caesars, Poseidon exerts a special pull on tourists, many of them grandparents shepherding grandchildren. On certain days, the place is overrun with people, so be prepared for crowds and wailing babies.