Mercer Caverns, Show cave in Murphys, California, US

Mercer Caverns is a show cave one mile north of Murphys, California, formed in a marble unit called the Calaveras Formation. Its chambers hold many stalactites, stalagmites and speleothems, including a large display of aragonite frostwork. The cave was mapped in 1986 at 3,389 feet long and 192 feet deep.

Walter J. Mercer, a gold prospector, found the cave around 1885 and filed a claim on it, giving the caverns his name. The site was later developed as a show cave, and in 1986 it was mapped to a length of 3,389 feet and a total depth of 192 feet.

The cave is named after gold prospector Walter J. Mercer, who discovered it around 1885 and filed a claim. Its large display of aragonite frostwork, a rare speleothem, is what visitors come to see. The cave was later renamed from "caves" to "caverns".

The standard tour descends 160 feet over 208 steps and climbs back up 232 steps, entering naturally and leaving through an artificial entrance. The cave was mapped in 1986 at 3,389 feet long and 192 feet deep; the map is posted on the cave's website.

The cave holds a large display of aragonite frostwork, a delicate crystal growth on the rock. The cave was mapped in 1986 at 3,389 feet long and 192 feet deep, and that map can be viewed on the cave's website.