Gunns Plains Cave was discovered in 1906 by -- of all things -- a possum.
While out hunting, Bill Woodhouse chased a possum down a hole and inadvertently found himself inside a massive chamber. The cave is one of only a few in Tasmania to contain water; an underground stream still flows through the cave, occasionally flooding and leading to closures. Although the cave is too cold for bats, it is home to giant freshwater lobsters, fish, eel, platypus, and millions of glow worms.