They may be woolly, innocuous and not known for their intellect, but sheep at Dover Castle have been playing an invaluable role.

The flock of 30 hardy Herdwick sheep, more common in the Lake District, are much appreciated by both archaeologists and conservationists.

With the advent of winter the sheep are settling in to pastures-new from the exposed surroundings of the fortress where they have spent three months.

Kent Wildlife Trust (KWT) and English Heritage formed a partnership to reintroduce sheep - last grazed at the site more than 150 years ago. Natural England is also a partner and providing funding.

Conservation grazing has helped maintain the biodiversity of chalk grassland for wild plants and animals and helps protect the fabric of the historic monument itself.

The castle grounds are designated as a Local Wildlife Site (LWS) on account of the rich diversity of chalk grassland plants and animals

Herdwick sheep are hardy, lightweight and adapted to graze steep slopes and forage on rough vegetation.

They were so much at home that only 22 could initially be tempted with sheep treats of sugar beet pellets at the initial castle roundup.

The stragglers were due to join them at Ham Fen, near Sandwich, until next spring when they will return.

* See the Dover Mercury, December 22, for a special two-page picture feature.