Digging deep: Marathoners go over a kilometre underground to set world records

October 29, 2025

A field of 55 runners from 18 countries have just ventured where no marathoners have gone before – 1,120 metres below the Earth’s surface – to complete the World’s Deepest Marathon inside Boliden’s Garpenberg zinc mine in Sweden.

And they set two new Guinness World Records in the process in an event that was held in the dark apart from the start / finish area.

It was intended to be a demonstration of mental and physical resilience, while showcasing the innovation and safety of the modern mining industry.

In an added twist, Minecraft was livestreamed in a mine for the first time by gaming creator Seapeekay.

The 55 runners had to overcome high humidity, temperatures of up to 30°C, gravel floors and almost complete darkness as they completed 11 laps of a 3.84 km tunnel to reach the full marathon distance.

The aim was to raise more than $1 million for the BecomingX Foundation and Wild at Heart Foundation.

And the two Guinness World Records – subject to verification – were for the Deepest Marathon and The Deepest Underground Marathon Distance Run (Team). rUN247