Today was a fascinating glimpse into life before email, a time when the Post Office was King and mail trundled around underneath London on 22 miles of track that made up the world's first driverless electric railway.
Opened in 1927, this ground breaking innovation meant that hundreds of thousands of letters, parcels and packages could be delivered around the country in a super fast turnaround time.
It never stopped, even during World War II and was a beacon of technological excellence, further enhancing the democratisation that was the Post Office and started way back in 1839 when anyone could communicate for the price of a stamp. Although the earliest origins date back to good old Henry VIII in 1516.
Definitely worth a visit, including a 15 minute trip around some of the old lines as well as lots of interactive games and some cracking old vehicles.
AND, an entire sheet of Penny Blacks, the very first postage stamp. Priceless.