The Farmlands Hidden Temple is a small secret underground area that is secluded within the trees near the path that leads to the Crypt of the Sacred Blood on the outskirts of the Farmlands.
The location of the Temple is simply located east of the 2nd stone signpost within the Farmlands forest labeled 'crypts'. Which is roughly halfway between the first stone signpost, and the Crypts of the Sacred Blood itself. The Temple can be be accessed by interacting with an angel statue that stands under a soft glowing blue light, which will reveal the Temple's secret entrance.
The Hidden Temple itself is rather short, and is guarded by only a couple of Gargoyles and Jade Gargoyles. At the end of its flooded hallway, there is an open area with an angel statue in the middle of the room. Interacting with this statue will reveal two Skeletons on either side of the room, in which the northern most skeleton will always drop a Puller Staff.