Regent's Canal towpath from Little Venice to Limehouse is London's most scenic running route. Completely flat, traffic-free, passes Camden Market, King's Cross, Victoria Park. About 8 miles total but you can exit at any tube station.

Start at Warwick Avenue tube, head east. Stretch through Regent's Park is gorgeous, Camden Lock has water fountains, Olympic Park section feels rural despite being Zone 2. Early mornings best — Fewer cyclists and dog walkers. Path gets muddy after rain but mostly paved.