The cave system consists of three separate chambers—Timpanogos, Middle, and Hansen caves—that have been connected by man-made tunnels. The caves are noted for their pink and white, crystal-filigreed walls and their tinted, delicate helictite formations; stalactites (stalactite and stalagmite), stalagmites, flowstones, and underground pools are also found in the cave. One of the stalactites (the Great Heart of Timpanogos) is shaped like a human heart. The name Timpanogos is believed to be derived from a Paiute word meaning “reclining woman.” Naturally excavated millions of years ago by an underground stream, the first cave, Hansen, was discovered in 1887 by Martin Hansen, a local settler; Timpanogos Cave was discovered in 1915 and Middle Cave in 1921. Guided tours are given of the cave complex, which is reached by a steep foot trail that winds up the side of the mountain. The average temperature within the caves is 45 °F (7 °C).