Mang Uken, a 50-year-old resident of Wanaraja village, examines his tomato plants while small children shepherd their goats nearby. Several kilometers above them, local farmers harvest a crop of cabbage in the cool evening air. Boy scouts pass the afternoon laughing and playing at their camp near Lake Bodas. Yet in the midst of all this scenic beauty, potential disaster is lurking.

Only meters away, a structure juts out of the ground. It is the h