Lambert's Castle is an Iron Age hill fort in the county of Dorset in southwest England. Since 1981 it has been designated as a Site of Special Scientific Interest (SSSI) on account of its geology, archaeology and ecology.
The hillfort is situated on a broad northerly spur at the summit of Lambert's Castle Hill, which rises to a height of 256 metres (840 ft). 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 1.5 kilometres (0.9 mi) to its south, and Pilsdon Pen is about 5 km (3.1 mi) to its north-east.
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.
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.
Plateau surface of Upper Greensand
This is a mosaic of acidic grassland, open heath, scrubland and secondary woodland and comprises:
Sheep-fescue Festuca ovina, Sweet Vernal-grass Anthoxanthum odoratum, Early Hair-grass Aira praecox, Heath-grass Danthonia decumbens and Field Wood-rush Luzula campestris. Herbs present include abundant Tormentil Potentilla erecta, Heath Milkwort Polygala serpyllifolia, Cats-ear Hypochaeris radicata, Heath Bedstraw Galium saxatile, Heather Calluna vulgaris, Bell Heather Erica cinerea, Bristle Bent Agrostis curtisii, Bilberry Vaccinium myrtillus, bryophytes, lichen, Gorse Ulex europaeus, Western Gorse Ulex gallii, Bramble Rubus fruticosus, Bracken Pteridium aquilinum, Birch Betula spp., Hawthorn Crataegus monogyna, Rowan Sorbus aucuparia and Pedunculate Oak Quercus robur.
Upper Greensand / Gault junction
A zone of acidic bog vegetation consisting of: Purple Moor-grass Molinia caerulea, Common Cottongrass Eriophorum angustifolium, Sedges Carex spp. including Star Sedge Carex echinata, Green-ribbed Sedge Carex binervis and Flea Sedge Carex pulicaris; Bog Moss Sphagnum spp., Heath Spotted-orchid Dactylorhiza maculata, Devils-bit Scabious Succisa pratensis, Bog Asphodel Narthecium ossifragum, Marsh Violet Viola palustris, Meadow Thistle Cirsium dissectum, Wood Horsetail Equisetum sylvaticum, Lesser Butterfly-orchid Platanthera bifolia and Pale Butterwort Pinguicula lusitanica.
Unimproved, herb-dominated neutral grassland consisting of: Crested Dogstail Cynosurus cristatus, Common Knapweed Centaurea nigra, Red Fescue Festuca rubra, Yellow Oat-grass Trisetum flavescens, Quaking Grass Briza media, Spring-sedge Carex caryophyllea, Glaucous Sedge Carex flacca, Red Clover Trifolium pratense, Ox-eye Daisy Leucanthemum vulgare, Common Bird-foot-trefoil Lotus corniculatus. Less frequent species are Ladys-mantle Alchemilla vulgaris, Dyers Greenweed Genista tinctoria, Corky-fruited Water-dropwort Oenanthe pimpinelloides, Adders-tongue Ophioglossum vulgatum.
Wet areas in grassland
Soft Rush Juncus effusus, Sharp-flowered Rush Juncus acutiflorus, Oval Sedge Carex leporina, Common Yellow-sedge Carex demissa, Carnation Sedge Carex panicea, Common Marsh-bedstraw Galium palustre, Marsh Pennywort Hydrocotyle vulgaris, Ragged-Robin Lychnis flos-cuculi, Greater Birds-foot-trefoil Lotus uliginosus, Bog Pimpernel Anagallis tenella, Bristle Clubrush Isolepis setacea.
- Glow-worm Lampyris noctiluca
- Pearl-bordered Fritillary Boloria selene
- Small Pearl-bordered Fritillary Bolaria euphrosyne
- Lamberts Castle, Dorset: Walk of the week at www.telegraph.co.uk. Accessed on 22 Mar 2013.
- Media related to Lambert's Castle at Wikimedia Commons
- SSSI Citation etc from Natural England website