Moaning Cavern, about five miles northeast of Angels Camp near the town of Vallecito, is one of the largest single-room caverns in California. The main chamber is large enough to contain the Statue of Liberty. The cave was used as a burial site by Native Americans — archaeologists found human remains at the bottom of the vertical entrance shaft, suggesting people fell in over many centuries.
The cavern offers two types of tour: a conventional walkthrough tour via a spiral staircase, and a more adventurous rappelling descent down the original entrance shaft. The rappelling experience, which takes visitors down about 165 feet by rope, is popular and genuinely exciting for those comfortable with heights. The conventional tour takes about 45 minutes. It is a good half-day excursion from Angels Camp, combined with a visit to the nearby Calaveras Big Trees.