This location has a link with history showing the amazing pace of technological development in just over 100 years.
The subject of this cache certainly changed the modern world and could be considered a small step towards GPS, the Internet and many other technologies which are now an everyday part of our lives. At the time of this event, the building on the site was the Central Telegraph office.
The answer is on the wall - the wall of a very appropriate corporate headquarters. Don't linger under the watchful eye of the security cameras!
To claim this cache, mail us the exact wording of the circular grey historical plaque/sign on the wall. Mail the answers through our profile at the top of the page. The answer is NOT "City of London, Ward of Cheap"
Under no circumstances should you post the answers in your log and DO NOT POST PHOTOS OF THE ANSWER. You must physically visit this cache in order to log it, please do not abuse this requirement (I regret that I will have to delete logs that do not meet these requirements). When you email the answer then please remember to release your email address to enable us to reply.
Please check out the Geocaching Association of Great Britain offering support for Geocachers in GB.