Knightsbridge is an area right in the heart of central London which is most famous for Harrods and other upmarket shops like Harvey Nichols. There is an underground station which is on the Piccadilly Line and the area is easy to get to by local transport such as buses and taxi. After you have maxed out your credit card why not take a stroll to Hyde Park which is about 10 minute walking distance away. For night time there are numerous restaurants, bars and hotels like the Mandarin Oriental Hyde Park.