MAJOR work has started "not a moment too soon" to move an historic Purbeck landmark before it tumbles into the sea.

Clavell Tower has been perched on the cliff top at Kimmeridge Bay for the past 176 years but has become increasingly precarious as the rock it stands on crumbles away.

Geologists believe it could not have lasted more than another five to ten years, and building work would very soon have become impossible.

On Monday, the first stone was lifted in a £898,000 project by the Landmark Trust to rebuild the tower 25 metres inland.

The tower will be carefully dismantled and each stone numbered and recorded so it can be rebuilt in its original design.

But it will not be just a tower anymore, as the Landmark Trust are turning it into exclusive holiday accommodation.

Projects Officer Alastair Dick-Cleland said: "The public will still be able to visit the site whenever they want, and there will be open days to go inside.

"By letting it out, the building will generate an income and allow us to maintain it against the constant battering of the elements."

The cost of staying at the tower has yet to be decided, but the owners are expecting a lot of interest, despite being only 12 feet across and having no vehicle access.

"We label some of our holiday homes as "H" for "hardier", and I think this will probably get that label," said Mr Dick-Cleland. "But it's such a fabulous and romantic location that I'm sure we'll have a lot of bookings."

There is a precedent for this use at Clavell Tower, which was built by Reverend John Clavell in 1830 and acted as a guesthouse and observatory during the 19th century.

It was a favourite of Thomas Hardy and the inspiration for PD James' The Black Tower.

In the early 20th century, it became a coastguard look-out before being abandoned in the 1930s and falling into disrepair.

The project, which is expected to take 18 months to complete, won't save the tower forever.

Mr Dick-Cleland said: "Oh, it will certainly have to be moved again, but probably not for another 200 years.

"And hopefully its better condition will mean it doesn't have to be brick-by-brick next time."