There are basically 2 main zones; one clustered around the John Peel Boulder; obvious and enormous boulder with half a dozen probs on, and hard to miss, plus some satellite stuff.
Then there is the stuff walking up Sleepy Hollow; more a circuit than a cluster, and needs a bit of exporing to find the best boulders; better saved for a longer session.
Plus a few outlying bits up and down the glen.
No broken glass, but a tarp or carmat might be a good idea to keep mud and sheep poo of your feet. No broken glass, but some landings a bit rocky, otherwise soft peat, OK when dry, bog when wet.