Royal Botanic Gardens, Kew

Sprawling 326-acre UNESCO World Heritage botanical garden with 50,000+ living plants across Victorian glasshouses including the iconic Palm House and tropical Temperate House. Children's Garden designed for ages 2-12 features water play with giant lily pad stepping stones, treehouse canopy walk around a 200-year-old oak, bamboo tunnels, and earth-science activities like wormhole slides. Beyond that: climbing the 18m Treetop Walkway, exploring Kew Palace, the Great Pagoda, and discovering seasonal highlights like orchids and bluebells.