Ananova:

A Victorian sea fort off the coast of Portsmouth is on the market for £4 million.

No Man's Land Fort, a mile from the mainland, was originally built to house nearly 80 soldiers to fend off an attack from the French navy.

More than a century later, it has spent its recent life as a luxury hotel complete with 21 sumptuous themed rooms, two helipads and heated indoor swimming pool.

Now after the previous owner has been jailed and his company collapsed, the fort is once again on the market.

Rachel Halliday, spokeswoman for administrators KPMG, said: "We are letting people express an interest in the property before we invite offers for it, but it's expected to fetch up to £4 million

"This property is certainly a one-off and we have never had to sell anything this unusual before."

Built between 1861 and 1880 it needed a huge engineering effort to cut vast blocks of granite and transport them by barge to the building site, before they were lowered onto the sea bed for its foundations.

The fort is nearly 200 feet across and rises 60 feet from the sea. Its water supply comes from a borehole sunk into the seabed and it has its own electricity generators.

The exotic location is well known to passengers on the Isle of Wight ferry and it also featured as a backdrop to a 1971 Dr Who adventure called The Sea Devils starring Jon Pertwee.