Traps need to make sense. Somebody must of made it for a specific purpose.

The Pelezians, or 'clay people' were strongly bound to the earth. In fertile plains and valleys they lived their happy existence, peaceful, yet ever on their guard. Many nomadic attackers they defeated, until a different enemy came; their advanced technology and weapons (and magic) were beyond the skills of defenders. One-by-one their settlements fell, until the clay people were not more.

To the greedy students of the past, their heritage is but not forgotten.