Bharat Diamond Bourse (BDB) is world’s largest diamond bourse (exchange) located in Mumbai, India. It is spread over 20 acre plot, the Complex is designed to house around 2,500 small and large diamond traders in addition to Custom House, banks and other service providers who cater to the gem and jewellery trade.
The facilities at BDB include offices of diamond traders, four walk-in vaults, 24,500 safe deposit boxes, a 6,200-square-foot (580 m2) trading floor, strong rooms, lockers, customs clearance facilities with all the modern facilities required to carry day-to-day business.

Source: http://en.wikipedia.org/wiki/Bharat_Diamond_Bourse