In Sandy Hook’s Mortar Battery, there are a few passageways and tunnels. Most of them are locked away behind scary doors like this one; if you try to peer into the crack between the door and the wall, you can feel a steady cold breeze on your skin from the passageway. Once, many years ago, somebody had broken the lock on the door featured above, and I stood in the passage. I didn’t venture too far inside, because it was quite dark and filled with puddles of questionable depth.