The thought of a picnic basket suffices in bringing a smile on to anyone's face. Beneath its woven brown lid, there are sandwiches, eclairs, chilled bottles of ginger beer, biscuits and cheese. A sandbank is a similarly satisfying prospect; it is a tiny bit of land that may not even have trees and is secluded. Take a parasol with you and if you wish to wait on hand and foot, have a butler accompany you.