The Cotswold Water Park is the United Kingdom's largest marl lake system, straddling the Wiltshire–Gloucestershire border, north-west of Cricklade and south of Cirencester. There are 180 lakes, spread over 42 square miles (110 km2).
Folly Brook is a 2+1⁄4-mile (3.6 km) long brook in the London Borough of Barnet. It is a tributary of Dollis Brook, which is a tributary of the River Brent, which is a tributary of the River Thames. Folly Brook is lined for most of its length by narrow strips of woodland and scrub, with a good variety of trees and shrubs. It is one of the best streams in Barnet for small aquatic invertebrates, including several species of caddis fly and a stonefly, which are only found in unpolluted waters.
Windsor Hill is a 61.8-hectare (153-acre) biological Site of Special Scientific Interest in Princes Risborough in Buckinghamshire. It lies within the Chilterns Area of Outstanding Natural Beauty, and it is featured in the Nature Conservation Review. A small part is managed by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust, and access to this area requires a permit.
Queen's Wood is a 52-acre area of ancient woodland in the London Borough of Haringey, abutting Highgate Wood and lying between East Finchley, Highgate, Muswell Hill and Crouch End. It was originally part of the ancient Forest of Middlesex which covered much of London, Hertfordshire and Essex and was mentioned in the Domesday Book. It is now one of three Local Nature Reserves in the London Borough of Haringey. It is situated a few minutes' walk from Highgate tube station.
Herts and Middlesex Wildlife Trust manages over 40 nature reserves covering nearly 810 hectares north of London, in Hertfordshire and the historic county of Middlesex, part of which is divided between the London boroughs of Barnet, Enfield, Harrow and Hillingdon. It has over 21,000 members, and is one of 46 Wildlife Trusts across the UK. It is a Registered Charity, with its Registered Office in St Albans, and had an income in the year to 31 March 2014 of over £1.5 million.
Aston Rowant National Nature Reserve is located on the north-west escarpment of the Chiltern Hills, in the Chilterns Area of Outstanding Natural Beauty. It has an area of 159.1 hectares, and most of it is a 128.5 hectares biological Site of Special Scientific Interest. It is listed as a Grade 1 site in A Nature Conservation Review. The reserve is in several sections, mostly in the parish of Lewknor in Oxfordshire, with smaller sections in the parish of Stokenchurch in Buckinghamshire.
Stocker's Lake is an old flooded gravel pit of approx 90 acres (37.5ha) at Rickmansworth, Hertfordshire, England, within the Colne Valley Regional Park which is designated as a Local Nature Reserve.
Oak Hill Wood is a 10-hectare Local Nature Reserve (LNR) and a Site of Borough Importance for Nature Conservation Grade I, in East Barnet, London. It is owned by the London Borough of Barnet, and part of it is a 5.5-hectare nature reserve managed by the London Wildlife Trust.
Frogmore Meadows is a 4.6-hectare (11-acre) biological Site of Special Scientific Interest in Hertfordshire and Buckinghamshire, north of the village of Chenies. It consists of two meadows in the Chilterns Area of Outstanding Natural Beauty, next to the River Chess, one of which is a Hertfordshire and Middlesex Wildlife Trust nature reserve. The planning authorities are Three Rivers District Council, Dacorum Borough Council and Chiltern District Council.
Alpine Meadow is a 0.4 hectare nature reserve near Berkhamsted in Hertfordshire in the United Kingdom. It is a designated biological Site of Special Scientific Interest (SSSI), managed by the Hertfordshire and Middlesex Wildlife Trust and the planning authority is Dacorum Borough Council.
Roughdown Common is a 3.6-hectare (8.9-acre) biological Site of Special Scientific Interest in Hemel Hempstead in Hertfordshire. The planning authority is Dacorum Borough Council. The site is Common land, and it is owned by the Box Moor Trust having been officially brought by the trust in April 1886 from the Dean and Chapter of St Paul's. It is part of the Chilterns Area of Outstanding Natural Beauty. The Common is a steeply sloping chalk hill in south Hemel Hempstead.
Hunsdon Mead is a 34 hectare biological Site of Special Scientific Interest (SSSI) west of Harlow and east of Roydon in Essex. The site is partly in Essex and partly in Hertfordshire, and it is jointly owned and managed by the Essex Wildlife Trust and the Herts and Middlesex Wildlife Trust. The SSSI also includes part of the neighbouring Roydon Mead. The planning authorities are East Hertfordshire District Council and Epping Forest District Council. Hunsdon Mead is registered common land.
Oughtonhead Common is a 17.4 hectare Local Nature Reserve in the Westmill district of Hitchin, Hertfordshire. It is owned and managed by North Hertfordshire District Council. and home to the Oughtonhead Common nature reserve.
Howe Grove Wood is an 8.5 hectare Local Nature Reserve (LNR) in Hemel Hempstead in Hertfordshire. It was declared an LNR in 1997 by Dacorum Borough Council.
Weston Hills is a 17 hectare Local Nature Reserve in Baldock in North Hertfordshire. It is owned by Hertfordshire County Council and North Hertfordshire District Council (NHDC) and managed by NHDC.
Hill End Pit is a 0.7-hectare (1.7-acre) nature reserve on the site of a former chalk pit, in St Paul's Walden in North Hertfordshire. It was formerly managed by the Herts and Middlesex Wildlife Trust (HMWT). In February 2016 HMWT announced that three sites, Barkway Chalk Pit, Hill End Pit and Pryor's Wood, which HMWT managed on behalf of their owner, North Hertfordshire District Council, were to return to Council management as the Trust was no longer able to meet the cost. It has the largest colony of Azeca goodalli snails in Hertfordshire. Plants include viper's bugloss, cowslip and marjoram, there are butterflies such as common blue and gatekeeper, and many birds including woodpeckers.
Marshalls Heath is a hamlet and a 4-hectare (10-acre) Local Nature Reserve in Wheathampstead parish, Hertfordshire, England. The nature reserve is owned by Wheathampstead Parish Council and managed by the council together with the Friends of Marshalls Heath. It was purchased from The Queen's College, Oxford, in 1966.
Hilfield Park Reservoir is a 76.3 ha construction built in 1953 between Bushey and Elstree in Hertfordshire, and owned by Affinity Water. Declared a Local Nature Reserve (LNR) in 1969, it is managed by the Herts and Middlesex Wildlife Trust (HMWT). It is the oldest LNR in Hertfordshire.
