The Sky Garden at the top of the Walkie Talkie is a wonderfully serene spot to do some yoga – it's light, spacious and packed with foliage. The classes here follow a dynamic vinyasa flow style so expect to break a gentle sweat. During the week they take place at 6.30am which means you get to watch the city wake up as you practice your sun salutations. There are also weekend classes which begin at 8am (8.30am on Sundays), and you could make a morning of it and head to the Darwin Brasserie afterwards for brunch.