Highgate (highgate cemetery.org), Nunhead (fonc. In 1768 Hampton Court’s gardeners planted a vine to supply King George III with Black Hamburg grapes. Now, 250 years later, it’s the biggest grape vine in the world, with its own greenhouse and keeper. Every autumn you can buy the grapes from the Walled Garden. The palace gardens are full of blazing trees, as is (free) Bushy Park beyond. For an autumn yomp through central London, take the Diana Princess of Wales Memorial Walk in the 20th anniversary year of her death and follow the floor plaques on a sevenmile route through four royal parks, passing six of her London homes.