Greg Brick knew it was there, lurking beneath his city, hidden within the Minneapolis water and sewer system: an enticing geologic anomaly called Schieks Cave. For years, he’d read about this maze, carved through the sandstone by rushing water. But his first attempt to find it led to a dead end. Then, in 2000, Brick found a way in. When Brick arrived at the cave, he shined a flashlight into the thick darkness of the city’s underbelly. He found not just the natural void but also concrete walls that previous…
