BNPS.co.uk (01202 558833)
Pic: LandmarkTrust/BNPS

Clavell Tower in Dorset.

Fully booked...Holidays less ordinary spark a booking frenzy in Brits.

A charity which rents out historic buildings around Britain is celebrating a boom in business that has seen some of its properties booked out years in advance.

The Landmark Trust has transformed almost 200 of the country's quirkiest buildings - from medieval castles to Tudor towers and even a former pig sty - into unique holiday homes.

And they have become so popular with Brits looking for unusual places to escape to that some buildings are fully booked until 2016.

Top of the most popular properties are Luttrell's Tower, a Georgian folly near Southampton, Hants, and Astley Castle, a Saxon stronghold dating back to the 12th century in Nuneaton, Warks.

Other favourites include a Victorian pigsty near Whitby, North Yorks, which was built in the style of a Greek temple, and the London townhouse of 20th century poet John Betjeman.

The buildings have become such a hit among holidaymakers that they are willing to fork out thousands of pounds to stay in them.

While prices start at 10 pounds a night for cosy cottages in winter, a seven-night stay at the most popular properties in the height of summer can cost up to 3,000 pounds.

But the fees are then ploughed back into the upkeep and restoration of the properties.