Knightsbridge is a residential and retail district in West London, south of Hyde Park. With London's best high-end stores like Harrods and Harvey Nichols, as well as designer stores like Chanel, Gucci, Prada, Armani etc., all located on Sloane Street that runs north to south from Knightsbridge to Sloane Square, it is a shopper's paradise - provided you have a lot of money to splurge!
Of course, there are also other regular brands like Zara and H&M, but in order to avoid the long wait outside the fitting rooms of these stores, you might want to visit them in less crowded areas of London!
Besides an overpowering number of tourists, you will also find here plenty of restaurants and cafes out of which 'Harvey Nichols Fifth Floor Cafe' and 'Yo! Sushi' for Japanese food, are my favorite.