The Sage Temple Cave is found in the Sage Temple Ruins, which are southwest of Lookout Landing, on the east bank of the Regencia River.
Cave Location
The Sage Temple Cave is in the Sage Temple Ruins, southwest of Lookout Landing, on the east bank of the Regencia River. The entrance to the Sage Temple Cave is a hole that goes straight down in a piece of the stone ruins, at -1405, -0256, -0004.
Cave Features
There are Brightbloom Seeds near where you land in the water from the cave entrance, and the rest of the cave is blocked by a wall of boulders. The right side leads to a dead end, so use a heavy weapon, bomb flowers, or other methods to get rid of the boulders on the left side. You will find a treasure chest that contains a Knight's Claymore.
Go through the door near the treasure chest to find a stone that mentions a sword that was moved to the Thyphlo Ruins.
The cave's Bubbulfrog can be seen through the bars behind the treasure chest. To reach it, break the boulders in the middle of the area to find stairs leading up. Go up the stairs, and from the top of the building you can drop down into the area with the Bubbulfrog.