The Mayor of London cut a ribbon just over 800ft above the capital to welcome visitors to the highest vantage point in western Europe.
He was joined on level 72 of London's tallest building by its architect, Renzo Piano, for the opening of the attraction, The View from The Shard.
Mr Piano said: "This building is magic for a number of reasons."First, because it's in London, second, because it's so tall, and third, because this building is a part of London. It's a sense of London."It's sad when London is sad, it's joyful when London is brilliant and joyful."
More top news
Police in Southwark are appealing to the public for help in finding a teenage girl missing from Bermondsey.
Over 40,000 people picked up their packs to take part in the annual marathon in the capital.
The boyfriend of reality TV star Ferne McCann has been arrested on suspicion of attempted murder following an alleged nightclub acid attack.