The London Long Distance Walkers Association holds an annual Capital Challenge (started in 2017). Along way you take in London's finest parks and architecture. Celebrating the best of London's green spaces, the 28-mile route uses almost completely mud-free paths through public parks, over fine town squares and beside waterways. It passes through some of London's best open spaces including Royal Parks, Hampstead & Highgate, the Woodberry Wetlands, the River Lea, and Queen Elizabeth Olympic Park, and it includes some surprises along the way. The route is almost completely mud-free and passes a wide variety of shops and cafés along much of its length. Note that the LDWA does keep times during the event, but it is not a race.
--submitted by Jonathan Burnhams