For centuries, rice farmers on the island of Bali have taken great care not to offend Dewi Danu, the water goddess who dwells in the crater lake near the peak of Batur volcano. Toward the end of each rainy season, the farmers send representatives to Ulun Danu Batur, the temple at the top of the mountain, to offer ducks, pigs, coins and coconuts in thanks for the water that sustains their terraced fields.