Who's the toughest of them all?

The Tough Guy competition is often billed as one of the most gruelling physical endurance challenges in the world.

More than 11,000 adrenalin junkies competed in this year's challenge -- a 15km course, dubbed the “Full Brutal Jacket”, which included more than 250 obstacles said to induce “extreme fear or panic”.

First staged in 1987 in Perton, Staffordshire, near Wolverhampton, England, the challenge is held on a 600-acre (2.42 square km) farm in Perton, Staffordshire, near Wolverhampton, England, and is organised by Billy Wilson.

Here are some glimpses of the whacky event, held every year:

A competitor emerges from the water during the Tough Guy Challenge at South Perton Farm in Telford, England. All photographs: Dan Mullan/Getty Images

Competitors make their way through a mud pond.

A competitor emerges from a tunnel. 

A competitor sits in the mud after clearing an obstacle during the challenge.

Competitors make their way up a hill during the challenge.

A competitor leaps through a fire obstacle during the challenge.

\

Competitors make their way over a hurdle during the challenge. 

A competitor emerges from the water during the challenge.

Competitors make their way down a cargo net during the challenge.

Competitors make their way along a muddy trench during the challenge.

A competitor carries a smoke bomb.

A competitor emerges from the water.