A neglected 17th Century dovecote has been added to a list of historic landmarks in danger of decay.

Patcham Dovecote in Brighton has been placed on English Heritage's Buildings At Risk register, along with Austin Friars Chapel in Rye and Castle Goring in Worthing.

They are among almost 1,500 of the nation's most vulnerable Grade I and II listed buildings which have now been promised help and restoration.

The dovecote, which has 550 nesting boxes, stands within the gardens of Patcham Court farmhouse, off Vale Avenue, but has fallen into disrepair.

The circular flint building has 3ft-thick walls and is a scheduled ancient monument.

The 773-acre Patcham Court farm belonged to the Marquess of Abergavenny's family from 1439 until it was acquired by the Brighton Corporation in 1925.

The 18th Century Castle Goring was designed by Biagio Rebecca for Sir Bysshe Shelley. It features a flint and stone Gothic entry, a large glass dome, a spiral staircase and fluted Greek Doric columns supporting the ground-floor vestibule.

Architecture experts Ian Nairn and Nikolaus Pevsner, in their book The Buildings Of England: Sussex, wrote: "By the deepest standard, all this was fiddling while Blake's Albion was beginning to burn but what a splendidly sophisticated and self-aware end to an age!"

English Heritage described it as "the most complete example of the 'carnival-style' of the era", adding: "A fragile gem of a country house, the Grade I listed building now urgently requires major repairs."

The remains of 14th Century Austin Friars Chapel is now overgrown and the window tracery is suffering from stone decay.

English Heritage is confident it can repeat the success of its restoration programmes at 11th, 12th and 13rd Century Hastings Castle and 19th Century Herstmonceux Windmill.

A repair and development programme is under way at the castle and a preservation trust has been set up to care for the mill. Both have now been removed from the Buildings At Risk register.

Andy Brown, English Heritage's assistant regional director for the South-East, said: "This year's register shows we are making good progress, as well as bringing in new sites we hope to help in the future.

"We still have a lot more to do in Sussex but it is very rewarding to be able to save some of these nationally important buildings."

Some of the listed buildings will be featured in the forthcoming second series of BBC show Restoration, which aims to raise awareness of the threats to historic structures.

English Heritage offered almost £5 million in grants to 71 buildings in the past year but £400 million is still needed to repair all those on the register.