Explore Secret Stories Waddle the Wandle Tour, a self-guided interactive walking tour to enjoy whenever you want. This tour is part of an Ordnance Survey series of bite-sized, tongue-in-cheek stories for you to read out loud. Expect nutty nature, smelly smugglers, raucous royals you get the idea. In its heyday, the River Wandle was known as \"the hardest working river in London.\" Once boasting nearly 100 working mills along its banks, the nine-mile river has been an important part of London’s industries — from textiles and tobacco to calico and copper. Total length: 4.22 miles; Suggested age range: 7+ Purchase this Tour (and more) in the Secret Stories App, available for free download from Android Play and Apple App store. You\'ll find more details of the tour and what it contains in the app!