Devils Postpile National Monument

Devils Postpile National Monument is a U.S. national monument located near Mammoth Mountain in Eastern California. The monument protects Devils Postpile, an unusual rock formation of columnar basalt, "all closely and perfectly fitted together like a vast mosaic", and Rainbow Falls a waterfall on the Middle Fork of the San Joaquin River, which are also the two main attractions. The monument encompa... (Wikipedia)