Hovenweep National Monument
	This is Hovenweep Castle. The small holes in the walls were not only useful as peep-holes and for ventilation, but also were used as calendars. The sun shining through the holes and onto the opposing wall marked the equinoxes and solstices, important dates to farmers. Because of the thickness of the walls, some of the holes had to be diagonal, as opposed to perpendicular, to the wall. In the minds of the experts, this effectively proves the theory.