Royal Botanic Gardens, Kew

The Royal Botanic Gardens, Kew, span an enormous 121 hectares and have been listed as a UNESCO World Heritage Site since 2003. Its lush flora and fauna will make you forget you're in the London metropolis. Inside the gardens you'll find an 18th-century Chinese pagoda, ornamental buildings, specialized plant houses, and a stunning treetop walkway that crosses the canopy of a forest clearing, consisting of a 200-metre walkway 18 metres above the ground. The grounds also house Kew Palace, originally purchased by George III as a residence for the royal children. Many princes and princesses were raised here. It was later used as a summer residence for the British royal family.