The Three Peaks Trial is an organised challenge walk arranged each year in March by the Cardiff Outdoor Group. Since 2010 Longtown Mountain Rescue Team provide support with marshalls on all the mountain top checkpoints.

The Walk was first held in March 1963 and was designed for less experienced walkers who wanted to test their powers of endurance and skill at map reading. It is now the oldest challenge walk in the UK. 

Over the years the event has been modified so in 2025 there is a choice of four other routes.

The money raised in the 2025 Three Peaks Trial will be split between the Longtown Mountain Rescue Team, the National Trust, owners of Sugar Loaf and Skirrid Fawr, for footpath maintenance and at least one other charity (charity decided November 2025).