The GateKeeper - The Blue Tombstone
An environment idea for The GateKeeper.
In an alien world of The Gatekeeper, there are gates (portals) that connect to one another, hidden in various locations. One of these gates is supposed to be connected to the Earth. After he gets sent to this world, the protagonist Peter travels around to find the right gate that will take him back home.
Peter finds out there is a slab of stone located in a canyon region. This stone is known to collect the remaining life force from recently deceased organisms and use it as the glowing blue energy source to activate the gates, which gave it the name "Blue Tombstone." Peter visits the tombstone in search of hints to get back home. Gon, knowing that the key to finding the gate to Earth is hidden within the tombstone, stalks Peter from a distance in order to snatch the hint from him.