Nemetons were the sacred groves of the Druids, priests, philosophers,  of the Celtic realms. According to the Roman writers Pliny, Lucan, and others, Druids did not meet in stone temples or any permanent structure but met in the woods, in sacred groves of trees. 

Now the word Nemeton is a Gaulish word meaning sanctuary, temple, sacred wood.

Obviously, this is not a wooded area, but we can look at it as a sacred place housing sacred knowledge. 

The Nemeton is not an Order or Group

The Nemeton is a resource filled will knowledge to help Guide oneself.