Remember George III? He’s the dilettante ruler who, during his reign from 1760 to 1820, lost the American colonies and went crazy from suspected porphyria: see the movie The Madness of King George for the tragic tale. Kew is where he spent his childhood and went insane, and you can tour a piece of his vanished palace, recently restored with scientific exactitude. It’s only the size of a standard manor house and lacks interpretation except for some ill-advised histrionic audio enactments that no one pauses to endure. Upstairs in the little Queen Charlotte’s Cottage, an imitation of a humble village home, the Picnic Room is painted with vines across its vaulted ceiling. The work is attributed to King George’s daughter, Princess Elizabeth. In late April, the Cottage, which is at Kew’s southwest end, is surrounded by bluebells in bloom.