Royal Botanic Gardens, Kew

Better known as Kew Gardens, this botanical research centre and World Heritage Site contains plants from across the globe, with Victorian tropical greenhouses and a Chinese pagoda, while the Xstrata Treetop Walkway offers great views. The  Children’s Garden is designed especially for visitors aged 2-12 and includes an activity trail and a tree canopy walk. Daily 10am-6pm. Adult £18, child £6; charges for special exhibitions.