A fair proportion of these events relate to walking and I can thoroughly recommend the Walking Festivals at Prestatyn, and Trefriw, which are coming soon. Sooner still is the Excalibur Marathon which takes place across the Clwydian Range on May the 10th, starting at 8am.
This is in aid of Claire House children's hospice in Liverpool. This is a tough trail, either 26.2 miles or 13.1 miles, which can be completed as a walk or a run traversing the spectacular Clwydian Range of North Wales. With over 5500 feet of steep ascent, Excalibur is promised to "take you to the edge. Excalibur tests the limits of each and every person who attempts to conquer it. Both a head for heights and a brave heart are needed to complete this challenge. Do you have what it takes?" The website is a call up for "Adrenaline junkies, fitness fanatics, seasoned fell runners, ultra marathon runners and hill walkers." See you there?
You can find more information on their Facebook page, or Twitter.