This gallery is from one afternoon spent with a guide in the rainforest. It was a good day for hiking but the waterfalls are very popular so go early if you want any nice photos.
El Yunque means "The Anvil," and it is so called for its distinctive flat peak. The forest is part of Puerto Rican mythology: The Taíno Indians believed the rainforest was home to a benevolent god named Yuquiyú.

http://en.wikipedia.org/wiki/El_Yunque_National_Forest