MEXICO: After a villager notified authorities about a cave hidden beneath the Maya site of Chichen Itza, archaeologists crawled hundreds of feet through passages that were only 16 inches high in places. In the cave, they encountered hundreds of undisturbed ritual artifacts, including incense burners depicting the rain god Tlaloc. The region experienced a severe drought toward the end of the first millennium A.D., which may have compelled the Maya to descend into the cave and entreat the gods for rain.