Mark Twain Cave is a national landmark located just outside of historic Hannibal, Missouri. Discovered in 1820 by accident when a man was trying to locate his dog. It became a local attraction of unexplored passageways that sparked the imagination of children and adults. Samuel Clemens, under his pen name Mark Twain made this cave famous when he wrote about it his stories, notably, the book The Adventures of Tom Sawyer. Although Mark Twain’s books have come under scrutiny in recent years because of their controversial text, don’t let that stop you from visiting this natural wonder. The cave itself is a mysterious labyrinth of twist and turns ready to…