In the dense areas, most of the concentration is via medium- and high-rise buildings. London's skyscrapers such as 30 St Mary Axe, Tower 42, the Broadgate Tower and One Canada Square are mostly in the two financial districts, <answer>the City of London and Canary Wharf</answer>. High-rise development is restricted at certain sites if it would obstruct protected views of St Paul's Cathedral and other historic buildings. Nevertheless, there are a number of very tall skyscrapers in central London (see Tall buildings in London), including the 95-storey Shard London Bridge, the tallest building in the European Union.
What are the financial districts of London known as?
the City of London and Canary Wharf