A walking challenge, described as "pointless" by its own organisers, has grown so popular that it has had to turn people away.
The event began in 1979 when a Cambridge University math student decided to march from the town of March back to the city, all on a date in March. Known as the "March March march," the 48km hike has been held almost every year since.
This year, the event saw a surge in interest, with 44 participants compared to just 16 the previous year. Colin Bell, the lead official, said, "We had to turn people away. It seems like the event has gone viral." Bell, who joined the march in 1990 as a student, now heads the event and is known as the "Custos Martis."
On the morning of the march, participants take a train from Cambridge to March and then walk back, following a route that includes an old main road, a disused railway, and the River Ouse.
A tradition of the march is stopping to send postcards to the university's maths department during the 12hr trek.
Despite its quirky nature, the event continues to attract attention and grow in popularity.
Mr Bell said: "It's good to get out on the Fens with friends, see the sky and see some different places.
"It's pointless, but it's a nice walking challenge and that's why we do it every year.
"Sometimes you just want to do something because of the name. We climbed Everest because it was there, we go to to March because that's there."
The increased interest has confused Mr Bell, who mused: "Perhaps the world has gone slightly mad."