Mark Twain Cave
Show Cave · Hannibal, Missouri
A show cave a mile south of Hannibal, originally McDowell's Cave, and the oldest operating show cave in Missouri - it has been giving tours continuously since 1886. Samuel Clemens explored it as a boy in the 1840s and put it into Tom Sawyer as the cave where Tom and Becky are lost and Injun Joe dies, and into four other books besides. The walls carry thousands of signatures scratched or smoked on by visitors over two centuries, including, the cave says, Clemens's own.
300 Cave Hollow Road, Hannibal, Missouri, 63401, United States
Open daily year round with guided tours running through the day, generally from mid-morning to late afternoon and longer in summer. Closed Thanksgiving, Christmas Eve and Christmas Day. Tours are about an hour. The campground and the winery on site are seasonal. The cave is 52 degrees year round.