Hawaii's Lava Tube

The Thurston Lava Tube in Hawaii is a 600ft crazy tunnel that goes in the middle of a volcano. The moist passage is ten to forty feet high. The tunnel was made 300-500 years ago when molten lava erupted and formed the passage way. A fern forest will lead any tourist to a bridge that goes into the entrance of the volcano. It was discovered by a guy named Lorrin Thrurston in 1913.