A chance to visit more than 190 green spaces rarely opened to the public, including Eaton Square and the gardens of HMPs Wandsworth, Wormwood Scrubs and Holloway. Participating for the first time this year are the allotments at Fulham Palace and the hidden garden at the Goring Hotel. One ticket allows entry to all venues over the weekend. Several gardens offer activities for children and there’s also a cycle tour stopping off at selected central London spaces. Visit the website for details.