Lee Valley Regional Park is a 26-mile-long ribbon of green that follows the River Lea north from the Thames at Limehouse all the way up to Ware in Hertfordshire, taking in Waltham Cross at roughly the halfway point. Created by Act of Parliament in 1967, it stitches together former gravel pits, reservoirs, water meadows, sewage works, and industrial wasteground into a 10,000-acre patchwork of nature reserves, sports facilities and walking trails.
From Waltham Cross you can join the Lee Valley Walk towpath in either direction. Heading north reaches the Lee Valley White Water Centre within twenty minutes, then continues through quiet stretches of marshland and reservoirs popular with birdwatchers. Heading south takes you along the canal to the Olympic Park at Stratford in about three hours' walk. Bikes can be hired at several points; canoes too.