Lambert's Castle
Lambert's Castle is an Iron Age hillfort in the county of Dorset in southwest England. Since 1981 it has been designated as a Site of Special Scientific Interest on account of its geology, archaeology and ecology. The hillfort is designated a scheduled monument together with a bowl barrow, the sites of a post-medieval fair and a telegraph station. The site was on the Heritage at Risk Register but was removed in 2022 as a result of the Hillforts and Habitats Project.
The hillfort is situated on a broad northerly spur at the summit of Lambert's Castle Hill, which rises to a height of. There are steep natural slopes on three sides of the fort, and linear ramparts across the flat southern approaches. The site is owned by the National Trust. A car park is accessible from the B3165 road. There are two other hill-forts near Lambert's Castle: Coney's Castle is about to its south, and Pilsdon Pen is about to its north-east.
History
Lamberts Castle was built around 2,500 years ago; a prominent ditch and bank still survive near the western entrance. A fair was held here from 1709 to 1947, during which the hilltop was used as a racecourse.
Geology
The site consists of sands and marls of the middle Lias with the remains of Gault and Upper Greensand capping. There are strong outflows of springs at various junctions of the upper greensand and gault.
Ecology
This is a mosaic of acidic grassland, open heath, scrubland and secondary woodland and comprises: sheep-fescue, sweet vernal-grass, early hair-grass, heath-grass and field wood-rush. Herbs present include abundant tormentil, heath milkwort, cats-ear, heath bedstraw, heather, bell heather, bristle bent, bilberry, bryophytes, lichen, gorse, western gorse, bramble, bracken, birch, hawthorn, rowan and pedunculate oak.
Upper Greensand / Gault junction
This is a zone of acidic bog vegetation consisting of: purple moor-grass, common cottongrass, sedges including star sedge, green-ribbed sedge and flea sedge ; bog moss, heath spotted-orchid, devils-bit scabious, bog asphodel, marsh violet, meadow thistle, wood horsetail, lesser butterfly-orchid and pale butterwort.
Lower slopes
Unimproved, herb-dominated neutral grassland consisting of: crested dogstail, common knapweed, red fescue, yellow oat-grass, quaking grass, spring-sedge, glaucous sedge, red clover, ox-eye daisy, common bird-foot-trefoil. Less frequent species are lady's-mantle, dyer's greenweed, corky-fruited water-dropwort and adders-tongue.
Wet areas in grassland
Soft rush, sharp-flowered rush, oval sedge, common yellow-sedge, carnation sedge, common marsh-bedstraw, marsh pennywort, ragged-robin, greater birds-foot-trefoil, bog pimpernel and bristle clubrush.
Notable invertebrates