No Man's Land, a fort sitting in the Solent off the Isle of Wight, covers more than 6,000m2 of floor space and boasts a lighthouse, 24 bedrooms, an indoor swimming pool, jacuzzis and a roof garden, not to mention two helipads.
One of three forts developed on the recommendation of a royal commission in 1859, its job was to defend Portsmouth against potential attacks from French warships. These days it enjoys a quieter life after being restored in the 1990s as a venue for corporate events, parties and high-profile weddings.
Savills director Nick Sweeney, who is handling the sale, says that No Man's Land is a great buy because of the "size and strength of the building and its crazy location". He adds: "We have had interest from hoteliers as well as individuals wanting to see it because it is so unusual."