"LONDON'S FREEDOM FOR THE S.W SUBURBS."
So screams Charles Paine's retina-scorching 1926 poster, heralding the brand new extension of the Northern line* — back then, making it the longest railway tunnel anywhere.
This weekend marks 100 years since seven genre-shatteringly handsome Charles Holden stations** made their debut, as London's south-western suburbs were firmly plugged into the network.
People are (rightly) excited about this anniversary. Someone's even baked a Tooting Bec station cake. But if you can't wangle a slice of that, there's plenty of action to be had on the Northern line itself this Saturday (12 September), where TfL has organised a free Northern Line Morden Extension Centenary Treasure Hunt, as part of Open House festivities.
Picking up a clue pack at Morden station, you'll need to work your way through questions, and hop between the seven Holden stations, with TfL Ambassadors waiting at each, to check your answers and stamp the clue pack before you move on.
The hunt — which is not a race; you've got four hours to complete it — concludes at Clapham South station, where there's a chance to win a prize, although only if you've answered all the clues correctly!
Northern Line Morden Extension Centenary Treasure Hunt, starts at Morden station, 12 September 2026, 11am-3pm, free
*Or at least, the line that would become known as the Northern line.
**Pedants' note: Balham didn't open till that December
