The site straddles the Hertfordshire/Essex boundary.
History
Since the 1930s the area which was originally part of the River Lea flood plain has been the centre of the sand and gravel industry, as a result there are many mature gravel pits. Some of the lakes were used for land fill purposes. In a joint effort by the St Albans Sand and Gravel Co Ltd and the Lee Valley Regional Park Authority the area has been transformed, with much of the park a Site of Special Scientific Interest (SSSI) [1]
Hall Marsh Scrape. The lake was specifically constructed for the use by wildfowl. TL3710701742
Holyfield Lake. The 180 acres (73 ha) lake incorporates part of the River Lee Flood Relief Channel. TL3736604898
Hooks Marsh Lake The over- wintering bittern can be found here between December and March. TL3717502523
North Metropolitan. Better known as North Met Pit. Due to the many islands and inlets, the lake has an estimated shoreline of 4 miles (6.4 km). TL3679403257
Seventy Acres Lake. The bittern and the otter can be seen here. TL3742203097
Turnford Pits.TL3701204955 Small relics of unimproved grassland that preceded gravel extraction can be found adjacent to the lakes.