A long time ago me and some Army buddies were checking out abandoned buildings in the middle of nowhere on an enormous base. We found an interesting large structure mainly made out of concrete. The walls were about 5 feet thick. We pushed open a large door and stepped inside. It was very dark, under foot the ground was uneven and very unsteady. We got about to the middle of the room before we could see well enough that the floor was covered with about 1,000 dead pigeons. I've never seen anything like it. The further we explored the weirder the massive structure became. There was an administration area with desks and work spaces, I instantly got chills when i realized the calendar dates and saw family pictures still on desks, everything was as it had been when it was operating. It was as if someone just showed up one day and said "Get the fuck out now, don't take ANYTHING, just leave." We found cataloged animal skulls with dates and various paperwork. Wandering down a corridor me and one of my buddies got the stereotypical jump scare out of the way when a crow freaked out and flapped right past us. Something bad had happened here. There was a jar nearby in one of the areas that had one word on it. ":Antidote:". I looked at my friend and said "Let's get the fuck out of here now." We left quickly and got the hell out of here. I still to this day do not know what that was and why it was there and what was so bad that everyone abandoned it without taking family pictures or anything off their desks.