Thousands of hardy competitors worked their way through muddy tunnels, down giant water slides and across a freezing loch in the name of charity at the weekend.
About 2,500 participants took part in the gruelling Prime Four Beast Race, held just outside Banchory, on Saturday.
Organisers hope that the event will surpass last year’s donations total of £53,000 for Chest Heart and Stroke Scotland (CHSS), with the final amount raised for the charity to be revealed later this week.
The event was yesterday hailed as the most successful in the race’s history, with a record number of entrants crossing the finish line.
Competitors had travelled from as far as England, the Netherlands and Romania to test their mettle in Deeside.
A spokesman for CHSS offered “a huge well done” to everyone who braved the Knockburn Sports Loch for the challenge, saying they were all “absolutely amazing”.
He added: “It was a tough and breezy course made even more beastly with the icy loch and thick clay clag wall.”
Participants ran up the Hill of Kerloch and waded through the chilled waters of Knockburn Loch on the tortuous six-mile route punctuated by 30 challenging man-made obstacles.
Calum Grant, from Aberdeen, vowed to return after a successful first experience.
He said: “It was my first time running the event and I really enjoyed it.
“It was very well organised and thought out, and I will definitely be back next year.”
Women made up the the majority of 2018’s participants, with the youngest aged 16 and the oldest at 64.
This year’s event title sponsor was Prime Four, an international business park based on the outskirts of Aberdeen.
Fife Hyland, communications director at Drum Property Group, developers of Prime Four, praised those who took part on the chilly day.
She said: “The Prime Four Beast Race has been excellent this year.
“We are proud to be sponsor such a fantastic event, and one which keeps growing and growing.
“It was pretty cold on the day so a huge well done to everyone who took part.”