Here's a useful fact to remember when your legs are complaining near the end of the 9 Locks Challenge: there aren't actually nine locks anymore.

The winter edition of OP Events' unusual point-to-point 10K returns on Sunday 29 November, taking runners from the Bonded Warehouse in Stourbridge along the canal towards Brierley Hill. The sting comes late, when the route tackles the famous Delph Locks.

They really were nine once. The original flight was constructed between 1777 and 1779, but extensive rebuilding in the 1850s replaced seven of the original locks with six and reduced the total to eight. The Nine Locks name stuck and remains in use today.

For runners, counting them might be the last thing on their minds. The organiser describes the course as continually inclined, with canal-side running and a hint of trail before the Delph Locks provide the defining final challenge.

There is even separate chip timing for the climb, adding a King of the Hill contest within the 10K itself.

The event has grown significantly too. Official results show 334 finishers in 2023 and 470 in 2024, before 664 completed the winter challenge last November. A summer edition has since joined the calendar, with James Hoult and Meg Judge the fastest man and woman over the full 10K in May this year.

November brings runners back to the original winter challenge. It's 10K, it's uphill and, despite what the name says, there are eight surviving locks.

Somehow, 8 Locks Challenge just wouldn't sound quite right.

Entries are available now via the runABC race hub.

Image courtesy OP Events.