"Spa wars" between hotels have become unsubtle undertakings, with each inn attempting to outdo the other where it comes to design, pampering, and exoticism. The 10th-floor retreat at the Four Seasons Hotel at Park Lane starts with a distinct advantage: glorious views stretching all the way to Big Ben and the Parliament. As for the pampering, there's a sky-lit "vitality pool," individual relaxation pods, Hungarian skin care products, and a lounge where one can nosh on organic lunches.