The cache is a micro bottle top type - try to replace it exactly as you found it so that the troll doesn't know you were here! He spends a lot of his time walking in the forest so if you're lucky you'll miss him on your hunt, but his many spider friends will probably be at home so watch out :)
Rumour has it that the Ely Troll enjoyed partying with the world leaders when they came to stay just across the water at the Lough Erne Golf Resort during the 2013 G8 summit - but that might be a tall tale! Either way the forest was entirely locked down for the duration and some of the paths had foliage cut back and were smoothed - presumably for emergency access during the summit. The paths are therefore stroller accessible and free from mud or puddles.