The Lost World is a science fiction novel by British writer Sir Arthur Conan Doyle, published by Hodder & Stoughton in 1912, concerning an expedition to a plateau in the Amazon basin of South America where prehistoric animals still survive. It was originally published serially in the Strand Magazine and illustrated by New-Zealand-born artist Harry Rountree during the months of April–November 1912. The character of Professor Challenger was introduced in this book. The novel also describes a war between indigenous people and a vicious tribe of ape-like creatures.

Sir Arthur Ignatius Conan Doyle was a British writer and physician. He created the character Sherlock Holmes in 1887 for A Study in Scarlet, the first of four novels and fifty-six short stories about Holmes and Dr. Watson. The Sherlock Holmes stories are milestones in the field of crime fiction.