Mercer Caverns
Show Cave · Murphys, California
A narrow, vertical limestone cave just outside Murphys, found in 1885 by a prospector named Walter Mercer who was looking for water and fell into it instead. It has been open to visitors continuously ever since, which makes it one of the longest-running show caves in the state, and it goes almost straight down.
1665 Sheep Ranch Road, Murphys, California, 95247, United States
Open daily, generally 10:00 to 17:00 with reduced winter hours. Guided tours roughly half-hourly in season.