By Susan Mitchell

If you're currently searching for an exclusive home, and money is no object, there are some exquisite properties on the market around the world.

Whether you're tempted by an island paradise, fancy your own chateau or harbour ambitions to own an exclusive ski chalet, international estate agents have something to fit the bill.

Private Island retreats

The image of a pristine island - azure waves lapping at the shore, palm trees silhouetted in the setting sun is synonymous with paradise.

Greek shipping magnate Aristotle Onassis was one of the first to instill into public consciousness the concept of the private island as the ultimate retreat.

In the past 30 years he has been joined by Richard Branson, Nicolas Cage, Brooke Shields, Marlon Brando, Ted Turner and Diana Ross.

Farhad Vladi is one of the world's pre-eminent island brokers. "The psychology of private island owners is a desire to experience an alternative lifestyle away from the rat race," he says.

"Buyers want to get away and charge their batteries for two months, and then come back to civilization."

In the face of a major luxury slowdown, private islands have dropped slightly in price but are still selling well, according toVladi. There are only 100 to 120 "desirable" islands for sale at any given time, he says, ranging in price from $30,000 to $30 million.

A desirable island is anywhere from five to 1,000 acres in size, has an elevation of at least 15 feet and provides a harbour and several anchorage areas. It should also have a choice of beaches, so that one is always protected from the wind. And the more existing infrastructure - docks, landing ramps, roads, housing - the better. One of the most exclusive islands on the market at present is the fully-developed private island of Leaf Cay in the Bahamas. The island features a 1,500 foot airstrip, underground wiring and a desalination facility. Located in the Exuma Chain, the island has 15 acres above highwater.

The main house is about 278 square metres in size, with central air-conditioning. On the upper floor is the master suite, with his and hers bathrooms and a living room that opens to a covered veranda.

There are two guest bedrooms, two bathrooms, an eat-in kitchen, a dining room, a spacious living room and a covered patio downstairs. The adjacent guest and staff quarters is about 325 square metres in size. It is on the market with Vladi Private Islands for $20 million.

Vladi Private Islands (www.vladi.de; tel 00 494 0338989) is looking for €15 million for Isola Santo Stefano in the Pontine Archipelago, Gulf of Gaeta, Italy. Situated 93 miles west of Naples, the 62-acre island has a church and various houses.

Another tempting option is Alize, an elegant house on the island of Mustique in the Caribbean. Situated on eleven acres on this island in the heart of St Vincent and the Grenadines, the property has an infinity pool, a guest cottage and three two-bedroom staff cottages.

The property has clifftop gardens and panoram ic views over the island. Knight Frank is guiding $11.5 million.

Exclusive ski chalets

After years of controversial over development, severe restrictions on new building, and in some cases a total ban, are now in place in many favourite European ski resorts.

Combine that with high demand for apartments and chalets, as well as cheap air fares into Geneva and France, and the market looks set to stay strong.Some developers have been raising prices by 30 per cent overnight; agents predict that in some locations capital values could rise by half over the next five years.

The spectre of global warming has also become a talking-point. It has been suggested that some of the lower resorts could face declining snowfalls, which would in turn ensure further capital appreciation of properties at high altitudes.

When Roman Abramovich, the Russian billionaire who owns Chelsea FC, decided to buy a ski chalet, he flew straight to France. The oligarch set his sights on Courchevel 1850, so called because it is pitched at 1,850 metres in the French Alps.

It is traditionally a winter retreat for royals such as Prince Michael of Kent and King Juan Carlos of Spain, but it is fast becoming a playground for nouveau riche Russians.

Abramovich was reportedly unable to find suitable properties. That comes as no surprise, as top chalets in such resorts are hard to find.

Investors in Property has a 450 square metre chalet on its books for €6.5 million. Built on four floors, the chalet is in the Courchevel 1850 ski area at the foot of the Pralong chairlift. There is a separate three-bedroom apartment on the lower floor.

Those willing to venture across the Atlantic may be tempted by Aspen's glitzy reputation. With its Dior and Gucci shops and internationally renowned restaurants and hotels, Aspen is where America's big shots come to unwind.

When it comes to ski chalets and winter properties, Aspen is the quintessential luxury real estate market in the US. Over Christmas Aspen played host to countless celebrities. Many, including Michael Douglas and Kevin Costner, have bought property in the area.

One of the most exclusive properties on the market in Aspen at present is the Elk Run Ranch, which sprawls over 77 acres. It is on the market for $17.9 million with Mason and Morse Real Estate.

The trophy retreat contains 720 square metres of verandahs that overlook the gardens, a waterfall and two ponds. It also has a guesthouse and a tipi. a tradional Plains Indian habitation.

Castles and chateaux

A castle or chateau is generally considered to be the most sought-after trophy property, according to Alexander Kraft, European regional manager for Sotheby's International Realty.

"It tends to represent the fulfilment of a long-standing dream. Buyers tend to be very rich, high-end professionals and businessmen, who usually have various homes in the likes of London, Paris and New York," said Kraft, the castles and chateaux tend to be used as seasonal homes.

The majority of buyers seek restored properties of a manageable size. "People don't want the property to be too big. Generally, those between 500 and 1,500 square metres are in most demand."

Americans and Britons comprise the majority of buyers but Kraft said that there had been good interest from Irish buyers during the Celtic Tiger years.

Sothebys enjoyed its best year ever in 2003, according to Kraft. He said that while people have more money to spare when the economy is booming, the luxury market had not been badly affected by the global economic downturn.

"Between1999 and 2002 people were buying without negotiating. That is no longer happening,particularly at the ultra-high end, or the €10 million plus bracket. But if properties are well-priced they are selling," he said.

Villa Helios in Switzerland is one of the most luxurious properties on the market at present.The villa on Lake Lugano has 1,400 square metres if living space and a price tag of about €20 million.

The patrician three-storey villa dates back to 1902 and offers stunning views of the surrounding countryside. It has splendid terraces and a tower overlooking Lake Lugano, and according to Sotheby's is in perfect condition. There are separate buildings for staff and a boathouse, as well as parkland.

Castle Sigharstein in Salzburg, Austria, is on the market for €8 million less with Sotheby's. A magnificent baroque castle, it overlooks the Wallersee and has a history that dates from the 13th century. Mozart and the opera singer Maria Callas were among the guests who have stayed there.

The castle was revamped during the 1990s. Features include stucco ceilings, antique furniture, central heating, an elevator, an indoor swimming pool, a music room and a sauna. The property has 214 square metres of living space and lies on seven hectares of land.

Alternatively, Knight Frank is seeking offers in the region of €5 million for a 14th-century chateau at Perigord in the Dordogne region of France. The chateau has 17 bedrooms and is in 20 hectares of woodland. It is about 1,000 square metres in size.