El Yunque National Forest, formerly known as the Luquillo National Forest and the Caribbean National Forest, is located on the United States territory of Puerto Rico. It is commonly known as only El Yunque, a Spanish approximation of the aboriginal Taino word "Yu-ke," thought by scholars to mean "White Lands. " However the lightning storms that occur there were to the Spaniards the sound of a giant hammer hitting an anvil (yunque in Spanish).