a trip to Middle Earth no, not Tolkien's land of hobbits and
elves, although the sites may not look too different from that
fantasy world. Middle Earth is one area of the California Cavern
in Calaveras County, Calif. And yes, that is the Calaveras
County made famous by Mark Twain's jumping frogs. The cavern has
also hosted such notable visitors as Bret Harte and John Muir.
California Cavern is imbedded in limestone beds beneath the
Sierra Nevada foothills. Ten million years ago, hot brine pools
formed, dissolving much of the limestone and leaving giant
caverns, says Steve Fairchild, president and founder of
Underground Adventures, which maintains the cavern and offers
tours there. The limestone was then metamorphosed into marble
with the emplacement of the immense Sierra Nevada batholith
nearby. Speleothems began growing shortly after the caverns were
formed, according to dating from stalactite and stalagmite
growth rings. Moaning Cavern's spectacular speleothems are
other-worldly. Photo courtesy of Undergrou