Journey to the Center of the Earth
Subterranean fiction existed before Verne. However his book was different because of its well-researched Victorian science and its innovation to the science fiction subgenre of time travel. Verne's innovation was the concept of a prehistoric area still existing in the present-day world. The book was made into a movie in 1959. It inspired many other books, including J. R. R. Tolkien's The Hobbit.