For sale: Desirable residence. Must love sea views

"A world apart" is the estate agent's description - and for once they are probably not exaggerating. Privacy and remoteness are certainly assured at this particular property, but unfortunately, there is nowhere to park the car, only the helicopter.

Popping out to the shop for a pint of milk is also bit of the problem, although to compensate, there is a private borehole providing fresh water. And a great view of passing yachts.

Available to anyone with a few million pounds to invest in either a business venture or to obtain the ultimate in privacy, No Man's Land Fort, a 200ft diameter structure in the Solent, just off the Isle of Wight, is up for sale.

A familiar landmark for yachtsmen and ferry travellers, the fort, built in Victorian times, had operated for some years as a hotel and function venue to which guests were either ferried by boat or arrived at one of its two helipads. Despite attempting to break into the lucrative market of unusual marriage venues, it went out of business last year and has now been put up for sale by the receivers.

Nick Sweeney, the director of Savills handling the sale, says: "Without doubt No Man's Land Fort is the most extraordinary property offering security, privacy and a remarkable amount of space.''

Sitting in "The Lighthouse" - a self-contained apartment and observatory within the fort - made you feel like the captain of a ship, albeit one that did not move, he said.

No Man's Land Fort comes complete with all the trappings of a modern hotel - 21 guest bedrooms, gymnasium, swimming pool, jacuzzis, dining areas and bars - plus those helipads. A large glass dome covers the central area, formerly the Upper Gun Floor, creating a main piazza. Savills is inviting offers from buyers, describing it as: "A remarkable landmark ... it is the ultimate secure destination for business and pleasure.''

Such sybaritic luxury is a long way from the grim and windswept life that faced the soldiers stationed on the fort when it was completed in 1880. It is one of four such sea forts in the area, originally conceived in the 1850s to help defend Portsmouth against any attack from French warships. The others were Horse Sand Fort, Spitbank Fort and St Helens Fort.

The Victorians poured all their engineering expertise into the creation of the forts - massive granite blocks were cut and shaped on land, transported on barges and lowered into the sea to form a base for the fortress. The upper walls were covered in thick, armour-plated gun emplacements designed to absorb the shock of a barrage being fired. At a cost of £462,500 - a huge sum in Victorian times - No Man's Land Fort was the most expensive of the four to build. Ironically, by the time they were completed, the threat from the French had dissipated.

The forts were kept on as military bases and were fitted with anti-aircraft guns during the Second World War.

They were decommissioned and put on the market in the 1960s. But it was not until the mid-1980s that No Man's Land Fort was sold, to a property company which oversaw its conversion into a luxury hotel.

Spitbank Fort was bought by a private buyer in 1982, restored and opened to the public. Horse Sand Fort was taken off the market and retained by the MoD. St Helen's Fort is also in private hands.