St Paul's Cathedral is one of London's most famous parts of London's skyline, and it's like an old friend to me. But there is more to the famous dome than you might think, and it impacts massively on London's skyline, and has done so for years.
When the dome was built after the Great Fire of London in 1666, it caused a sensation. It was the first dome in England, and Londoners believed it was the work of the devil, as with no pillars under the dome, they couldn't understand how it stayed up.
But stay up it did, and the striking dome quickly became an important part of London's skyline.
In the 1930s, laws were introduced - named St Paul's Heights - to protect the view of the dome of the cathedral from a variety of different angles across London. Some, such as in the image below, impact on the immediate surroundings of the cathedral within the City of London, whereas others impact views from a much greater distance.
It impacts on the area so much that new buildings are created with these laws in mind. Some of the newest additions to the London skyline - like the Cheesegrater building or the Shard - are mocked or admired in equal measures for their unusual proportions, however they are designed so as not to fall foul of these precious sight lines.
The Cheesegrater (below left) is built on an angle to provide the all-important view of the dome, whereas the Shard (below right) tapers to a point. The latter building sits within two different sight lines, and occupies the minimum amount of space so as to abide by these laws and allow the view of St Paul's cathedral dome from south east London.
It doesn't just apply to central London. These sight lines extend out as far as 10 miles (16km) to 7 different places, usually all on elevated positions, such as Parliament Hill, Greenwich Park, and Richmond Park. Here in south west London, on a spot known as King Henry VIII's mount, the view of the dome is helped by a hole cut into the hedge!
And on the other side of the city, the tall hill at Alexandra Palace provides a great view over the rooftops to one of London's most beloved buildings.
So the next time you have cause to stop and look at this beautiful building, take a look around to see the impact it has had on London's skyline.