"Where is the centre of London?"

One of the most common questions that I get asked, when visiting London, is "Where is its centre?"

This is a difficult question to answer, as there is no correct, or true, answer. At least not an answer that will satisfy everyone. 

As London has changed throughout the centuries and its population has grown from 250,000, in 1663, to over 8 million today, its centre is hard to locate.

But, with satellite data, and people 'pinging' their locations, accuracy becomes more important.

So, let's take a look at where the centre of London is... Currently.

London's earliest central point was established, in 1663, with the original Charing Cross. This was erected by King Edward I in honour of his dead queen Eleanor. Today, a plaque marks this spot where all distances to London are measured from. 

The plaque is set into the ground behind the Equestrian Statue of King Charles I, on the traffic island directly south of Nelson's Column. 

However, as London has grown its centre has moved and various people and companies have suggested it to be in different locations.

For many years people believed that the 'London Stone', on Cannon Street, was the centre of London.

In 1966 Harry Hyams, a property developer, called his skyscraper on New Oxford Street 'Centre Point'.

In 2010, using a cardboard cut-out of London, the 'gravitational' centre was unscientifically established as being 900 metres from Lambeth North station. The experiment involved balancing the cardboard cut-out on a drawing pin. 

In 2014, an electronic map was traced into a computer software programme, which allowed for much more precision. The result pinpointed, to within 40cm, the 'gravitational' centre as being somewhere in Greenham Close, just over 150 metres from Lambeth North station.

The latest data, using mapping techniques used by the British Army, places the centre 900 metres to the east of the statue of King Charles I, on Victoria Embankment, beside an iron bench outside King's College London. This is said to be the 'geographical centre' of London.

But this looks set to change, again, as there are talks to absorb Slough into Greater London, thereby changing its centre once again.

And, with G.P.S., new mapping techniques and A.I., this question will continue to spark debate for decades, if not centuries, to come.

This all means that should London's centre be definitively defined, then all road signs indicating distances to London would need replacing. Which brings up the question, "Who would pay for that?"

What does surprise me is that, after so many centuries, the centre has not really moved, but has been centred within a mile of its original position.