Bastille of Agility is missing

I was in a Forest Herbarium when I arrived at a Bastille of Agility map marker. All I found were three pillars around the edge of the POI and flat ground where structures would usually go. I looked on top of the three pillars and no Echo. I looked around the hill in case there was a cave, but no luck. The bug shot is taken from the top of one of the pillars.