This is my local labyrinth, a chalk swirl in the grass with a single path to the centre. It sits on Scrapyard Meadow, a landscaped mound between the railway viaduct and Tower Hamlets Cemetery. Look out for it next time you're on a train out of Fenchurch Street. The labyrinth's eight years old, has a 'classical seven-circuit' design and takes two minutes to walk round. It's a lovely thing to have nearby, ideal for a contemplative stroll or for giving a small child something meaningful to run around, and is surrounded by wild flowers in the summer.
So here's my attempt at listing London's labyrinths, which I'm defining as walkable continuous paths with no dead ends. My list is mostly cannibalised from websites here and here, especially here. I've already written a post on London's five hedge mazes, so you'll not find Hampton Court etc listed below. I have not been able to check these in person.