Where exactly is London and Kuala Lumpur?

I've always been wondering where exactly is London?

When we say the distance between London and Edinburgh is 535km, where exactly in London is that measured from?

I found the answer two years ago from a chanced discussion with another Engineer but decided to write about it now because I have found the physical reference point.

In London, the point of reference is nearby Trafalgar Square where the statue of King Charles I now stands. A plaque can be found on the floor behind the statue stating that mileage distances on road signage are still measured from this point. Why is it there, you can find out here.

Statue of King Charles I

Location of plague behind statue

The plague written with "..on the site now occupied by the statue of King Charles I was erected the original Queen Eleanor's Cross a replica of which stands in front of Charing Cross Station. Mileages from London are measured from the site of the original cross. "

There you go, another interesting find in London!

What about Kuala Lumpur? I've also Googled the same for Kuala Lumpur. Apparently, no answer was found.

Fortunately, I knew the answer. Back in 2005 when I was a Highway Engineer in Malaysia, I was once asked the same question about KL when I gave a presentation to UK's Institution of Highway & Transportation. The answer was the main Post Office in Kuala Lumpur.

I know this is silly but if the distance between London and Kuala Lumpur can be measured based on the two references, it is 6,553 miles or 10,554km.