CLASSIC Italian gardens are paradoxical places, celebrating sun and shade, earth and sky, the green of hedge, the crunch of gravel, the play of moving water -- just about anything but a profusion of flowers. In a country as dry and hot as Italy in summer, blooms and blossoms turned out to be far too complicated and expensive to maintain. So although Italy was the first European country to be dazzled by bulbs from the East and West Indies, the Americas and South Africa -- tulips, daffodils, narcissus -- in the 17th century, flowers gradually disappeared from the classic Italian garden. Increasingly, architects focused on perennial greens, cool stonework and the sound of water to soothe eyes and minds burning from the fierce sunlight that bakes the peninsula much of the year.

Labyrinthine designs of ilex, laurel, cypress or box -- interspersed with pools, fountains or cascades of water and underplanted with cool gray-green sage or well-trained rosemary -- are set among paths of gravel or hard-packed earth, and play off walls or balustrades of stone and stucco. Arbors, pergolas, grottoes and statues from myth or antiquity also decorate the individual ''rooms'' of a classic Italian garden, outdoor spaces that are as carefully planned as the rooms of the house itself and that fit the landscape as well as their inhabitants' needs.

''It is hard to explain to the modern garden-lover, whose whole conception of the charm of gardens is formed of successive pictures of flower-loveliness, how this effect of enchantment can be produced by anything so dull and monotonous as a mere combination of clipped green and stonework,'' wrote Edith Wharton, an early devotee, in her 1904 book ''Italian Villas and Their Gardens.''

But Wharton, who visited dozens of such gardens to research her book, was convinced that classic Italian gardens were among the most special places on earth: ''The traveler returning from Italy, with his eyes and imagination full of the ineffable Italian garden-magic, knows vaguely that the enchantment exists; that he has been under its spell, and that it is more potent, more enduring, more intoxicating to every sense than the most elaborate and glowing effects of modern horticulture . . .''

Classic Italian gardens, especially those of Renaissance design, have mostly been hidden behind the thick, high walls surrounding the castles and villas of the Italian aristocracy since their inception. Even in their home country they remain largely unappreciated, many still private and open to the public rarely if at all. Indeed, Italians who love gardens lament that their countrymen are generally more familiar with the concept of the romantic English garden or the formal French garden than with the home-grown variety.

But as Italy's 20th-century aristocrats try to balance bank accounts, private gardens that in some cases were planted centuries ago are being opened to the public. After seeing several, from Vignanello in central Italy to Florence, and the Verona and Vicenza areas farther north, one easily becomes taken with their particular charms. Visiting them requires planning, though; they are open on a limited basis, mostly to groups of 10 or those willing to pay an equivalent fee.

Castello Ruspoli

When Ottavia Orsini married Marc'Antonio Marescotti, the Count of Vignanello, at the start of the 17th century, she, like many a bride, determined to plant a garden at her new home 40 miles north of Rome near Viterbo. Home, which started as a ninth-century Benedictine monastery that was first turned into a fortress and later into a more livable castle, dominated a steep, rocky outcrop. Before she could even think of planting, however, Ottavia had the matter of soil to attend to: her future garden had none. So Ottavia, the daughter of the creator of Bomarzo -- the garden to the north whose 16th-century Park of the Monsters was filled with exotic animals and other bizarre figures carved in stone -- ordered tons of dirt carried to the site by ox cart to construct an earthen plateau over the rocky crags.

Nearly 400 years later, Ottavia's garden at the Castello Ruspoli in Vignanello is considered one of the purest Renaissance gardens in all of Italy. The intricate designs she laid out remain intact, says Princess Claudia Ruspoli, though today the elaborate plantings are in box hedge instead of the sage and rosemary that once traced Ottavia's elaborate geometric patterns.

Visitors looking out from the castle windows over the spacious central garden are rewarded with the most dramatic view: a perfect rectangle edged in green, crossed by four avenues of packed earth and divided into 12 parterres of box hedge laid out with geometric precision around a central fountain. Ottavia's own initials, OO, are visible in the central parterre closest to the castle moat. Utterly hidden is a smaller sunken ''secret garden,'' a standard element of Renaissance plantings, where the family could spend time outdoors away from the more public reception areas of the main garden. Today it is filled with roses, irises and dahlias, in beds shaped into diamonds, triangles and circles.