The Mysterious Cave Naupa Iglesia

The mystery behind this cave is an enigma of ancient structures that were built here long ago. I voyaged to Naupa Iglesia (Naupa Huaca) and investigated the cave. It has this strange andesite stone structure infront of the cave overlooking the valley. It also has this mysterious false door or alter that is cut onto the side of the cave. But in the back of the cave, it's blocked off by piles of stone.

Who do you think built this place, and why? Also, what do you think is in the back of this ancient cave?