The River Lea is one of England's most historically significant and diverse coarse fishing rivers, stretching approximately 68 kilometres (42 miles) from its source in Leagrave, Luton in Bedfordshire, through Hertfordshire, along the Essex border, and into Greater London where it meets the River Thames at Bow Creek. Rising in the Chiltern Hills at an elevation of around 115 metres, the river descends through a wide variety of landscapes — from agricultural countryside in its upper reaches to increasingly urban environments as it approaches London. This geographic diversity gives the Lea a remarkable range of habitats and fish species, making it one of the most productive and varied coarse fishing rivers in the southeast of England.