Beyond Thirty is a short science fiction novel by American writer Edgar Rice Burroughs. It was written in 1915 and first published in in February 1916, but did not appear in book form in Burroughs' lifetime. The first book edition was issued by Lloyd Arthur Eshbach's Fantasy Press fanzine in 1955; it then appeared in the collection Beyond Thirty and The Man-Eater, published by in 1957. The work was retitled The Lost Continent for the first mass-market paperback edition, published by Ace Books in October 1963; all subsequent editions bore the new title until the Bison Books edition of March 2001, which restored the original title.