In the stillness, we could hear splashing fountains. Stars shimmered in a reflecting pool. We basked in the solitude.

It was a far cry from earlier in the day, when we jostled with some of the 8,000 visitors who descend daily on Europe's finest example of Islamic architecture - a walled city of medieval palaces and gardens perched on a hill overlooking the southern Spanish city of Granada.

But as we approached the citadel's main square, we realized that we weren't alone.

Ever so faintly, we could hear the whispers of a bamboo flute. We followed the music to a park bench, which offered a sweeping view of Granada's white-washed houses.

There, against the moonlit glow of the ramparts, we could make out the silhouette of a young woman. Seated cross-legged, her slim form perfectly still, she made no attempt to acknowledge our presence. Instead, she seemed to drift into a trance as she weaved a musical spell around her.

We sat across from her and listened, mesmerized.

In that moment it was easy to see how the original inhabitants - the Muslim sultans and their 2,000 courtiers - viewed this oasis as heaven on earth.

While the rest of Europe was plunged into the Dark Ages,

Moorish magnificence blossomed inside the Alhambra: exuberant gardens, ornate walls carved in Muslim verse and water, water everywhere.

We had come to southern Spain to fulfil a romantic traveller's dream: to spend a night within the walls of this ancient wonder. Only two hotels boast such a privileged location: the Hotel America, a budget option, and the Parador de Granada, a luxury hotel that has become so popular rooms need to be booked at least six months in advance during high season.

For one night, we had a room at the parador - one of dozens of such hotels run by the Spanish government in historic buildings including palaces, castles and monasteries.

By day, our parador granted us easy access inside the Alhambra's tightly controlled palaces and gardens. From its gated courtyard, it was a two-minute stroll down a cobblestone street to the sultan's palaces, the highlight of any visit.

By night, after the palace gates closed, we were free to wander the grounds, which are laden with wisteria and fragrant orange trees.

The hotel is a jewel in itself. During the ninth century, it served as the home of a Muslim aristocrat. In 1492, when Catholics reconquered Granada, putting an end to 800 years of Muslim rule in Spain, the building was converted into a Franciscan convent.

Today, the parador's mix of Moorish and Christian detailing is amazingly well-preserved, providing a stark contrast to the spa bathrooms and smart-card activated lights in each room.

At the hotel's centre is a Renaissance courtyard and in the back, the dining room and outdoor terrace provide beautiful views of the sultan's summer palace.

We retreated here after a day of sightseeing, as dusk cast a pink glow over the hills.

By candlelight, we dined on regional specialties such as cod, prawns and some of the most intensely delicious manzanilla olives I had ever tasted. A bottle of albariño wine refreshed our palates.

After our meal, as we took our midnight stroll, the haunting strains of the young woman's flute wasn't the only music to reach our ears.

We could hear the Alhambra come alive with the harmony of water in all its crystalline voices: cascading, bubbling, gushing, gurgling, trickling, and drip-dropping playfully.

Water, so rare and precious in most of the Islamic world, was the purest symbol of life to the Moors.

Of his visit to the Alhambra, the poet and Nobel laureate Juan Ramon Jimenez wrote: "I heard the music of my life and my blood in the flowing water."

In the moonlight, far from the madding crowd, so could we.

• Visiting the Alhambra: Advance reservations and tickets (from $20 per person) are required if you want to visit the Alhambra's palaces and gardens. For more information, go to alhambra-tickets.es

• Where to stay: The Hotel America (hotelamericagranada.com) and the Parador de Granada (paradores.es) are located next to each other along the Calle Real de Alhambra in Granada. Rooms at the America range from $80 to $260 a night; rooms at the parador start at $450.

• Night visits: If you don't stay at either hotel, you can still take in the Alhambra by moonlight. Late-night visits (until 11:30 p.m. during high season) are easy. No reservations are needed; buy your ticket on arrival at the main gate. The night visits include only the Nasrid Palace, not the fort or gardens.