Do not be afraid to stray out of central London. You will definitely find the best parks.
Brockwell is Brixton and Herne Hill's "garden". In the summer, you'll see everyone from sun worshippers topping up a tan, to BMX riders getting ready for a race. You'll find the Lido if you want a swim or the fantastic cafe in Brockwell House. And don't miss the walled garden. Serenity in the city.
Norwood Rd, London SE24 9BJ, UK