PM Narendra Modi on Sunday inaugurated Surat Diamond Bourse, the world's largest office building with a 67 lakh sq ft built-up area. The office complex has nine 15-storey towers with a 24-ft-wide central 'spine' corridor that connects over 4,700 office spaces. The office complex, which can accommodate over 67,000 professionals, also has safe vaults and a jewellery mall.