The Opera Terrace was recently refurbished, its large conservatory painted turquoise and hung with tent-like turquoise drapes to block out the sun: in fact, it's not unlike drowning in the Pacific. The bar, where the outside terrace is at its narrowest, is extremely loud and pretty crowded indoors; a contrast which makes the peace of the restaurant seem positively sepulchral.
The terrace, though, is the real point: providing a perfect spot for leaning over the balustrade and sneering at the people below. This is a good-natured bar, but you'll need not to be feeling misanthropic to enjoy it there in the evening.
The Opera Terrace, 45 East Terrace, Covent Garden, WC2 (071-379 0666)