The correct answer to this open question is "Caves."
In paleolithic times communication with the spiritual world is thought to have been largely conducted in Caves.
When explorers and archeologists had visited and studied some caves, they have found pictograms and human representation on the wall of the caves where it also appears rare figures of gigantic humans or strange species that it could be interpreted that if they were some kind of gods to humans in paleolithic times. An example of this could be the Cave of Altamira, in the northern region of Spain.
During the Old Stone Age or paleolithic times. humans used stone, wood, and bones as useful tools for their daily living.