Defense Points: 900
Enemy Spawn Point (Ground): Three
Enemy Spawn Point (Air): One
Target to protect: One
The Chiseled Cavern is a short walk away from the West Seal Stone. There's a Sentry Crystal pedestal there that you can activate to transfer the defensive sentry crystal. Concentrating your defenses in the narrow path near the pedestal is crucial in preventing the enemy from reaching the seal stone. Surprisingly, this position is the easiest to defend in this map.
The Dark Crevice is where the heavy traffic will arrive as enemies here are equivalent to two entry points. They'll primary attack the East Seal Stone but they'll also branch off and take the other path leading to the West Ancient Idol itself. Barricading this part can require high maintenance so the best way to do it is to defend the Seal Stone by placing defenses on the ramp while blockade the alternate path so the defender(s) assigned to the Chiseled Cavern path can assist in defending both paths.
The last part is the narrow Mountain Path, which leads directly to the East Ancient Idol. You can place defenses in the lower path but someone has to dedicate defending it full time.