Actually there are three Wedge Tombs in this field (Cl. 10, Cl. 11 and Cl. 15), but when I visited Gleninsheen, back in 2008, I was not aware of Cl. 10.
This nice little tomb lies in the south west corner of the field and lies closest to the road (R480), from which you can clearly see it.
So if you visit Poulnabrone, don’t hesitate also to include this lovely tomb to your itinerary.
Visited May 2008