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The Millhead Stream is a minor tributary of the River Lea in England. The stream flows north to south across the Waltham Abbey flood plain and through the site of the former Royal Gunpowder Mills.

The Royal Gunpowder Mills are a former industrial site in Waltham Abbey, England.The Mills are an Anchor Point of the European Route of Industrial Heritage, (ERIH), set in 175 acres (0.71 km2) of parkland and containing 21 buildings of major historical importance. It was one of three Royal Gunpowder Mills in the United Kingdom (the others being at Ballincollig and Faversham), but Waltham Abbey is the only site to have survived virtually intact.

Lee Valley Regional Park is a 10,000-acre (40 km2) 26 miles (42 km) long linear park, much of it green spaces, running through the northeast of Greater London, Essex and Hertfordshire from the River Thames to Ware, through areas such as Stratford, Clapton, Tottenham, Enfield, Walthamstow, Cheshunt, Broxbourne and Hoddesdon in an area generally known as the Lea Valley.

The canoeing races at the 2012 Olympic Games in London were contested in two main disciplines: the slalom, from 29 July to 2 August, and the sprint, from 6 to 11 August. The slalom competition was held at the Lee Valley White Water Centre and the sprint events were staged at Eton College Rowing Centre, at Dorney Lake, known as Eton Dorney.

The Lea Valley, the valley of the River Lea, has been used as a transport corridor, a source of sand and gravel, an industrial area, a water supply for London, and a recreational area. The London 2012 Summer Olympics were based in Stratford, in the Lower Lea Valley. It is very important for London's water supply, as the source of the water transported by the New River aqueduct, but also as the location for the Lee Valley Reservoir Chain, stretching from Enfield through Tottenham and Walthamstow.

The Lee Flood Relief Channel (FRC) is located in the Lea Valley and flows between Ware, Hertfordshire, and Stratford, east London. Work started on the channel in 1947 following major flooding and it was fully operational by 1976. The channel incorporates existing watercourses, lakes, and new channels.

The Cornmill Stream and Old River Lea is a 24.6 hectare biological Site of Special Scientific Interest in Waltham Abbey, Essex.

Waltham Common Lock (No 10) is a lock on the River Lee Navigation at Waltham Cross in Hertfordshire, England. The lock is located in the River Lee Country Park and stands close to the Broxbourne White Water Canoe Centre. At the tail of the lock is the Powdermill Cut dug in 1806 to connect the Waltham Abbey Royal Gunpowder Mills directly to the then-new navigation.

Waltham Town Lock (No 11) is a lock on the River Lee Navigation at Waltham Cross, Hertfordshire. The lock is located in the River Lee Country Park which is part of the Lee Valley Park. The adjoining Showground site now known as the Broxbourne White Water Canoe Centre has been chosen to host the canoeing event in the 2012 Summer Olympics.

Lee Valley White Water Centre (previously known as Broxbourne White Water Canoe Centre) is a white-water slalom centre, that was constructed to host the canoe slalom events of the London 2012 Olympic Games. On 9 December 2010, Anne, Princess Royal officially opened the venue which is owned and managed by Lee Valley Regional Park Authority.