At the Mountains of Madness is a science fiction-horror novella by American author H. P. Lovecraft, written in February/March 1931 and rejected that year by Weird Tales editor Farnsworth Wright on the grounds of its length. It was originally serialized in the February, March, and April 1936 issues of Astounding Stories. It has been reproduced in numerous collections.
The story details the events of a disastrous expedition to Antarctica in September 1930, and what is found there by a group of explorers led by the narrator, Dr. William Dyer of Miskatonic University. Throughout the story, Dyer details a series of previously untold events in the hope of deterring another group of explorers who wish to return to the continent. These events include the discovery of an ancient civilization older than the human race, and realization of Earth's past told through various sculptures and murals.
The story was inspired by Lovecraft's interest in Antarctic exploration; the continent was still not fully explored in the 1930s. Lovecraft explicitly draws from Edgar Allan Poe's novel The Narrative of Arthur Gordon Pym of Nantucket, and he may have used other stories for inspiration. Many story elements, such as the formless "shoggoth," recur in other Lovecraft works. The story has been adapted and used for graphic novels, video games, and musical works.
The story is narrated in a first-person perspective by the geologist William Dyer, a professor at Arkham's Miskatonic University, aiming to prevent an important and much publicized scientific expedition to Antarctica. Throughout the course of his explanation, Dyer relates how he led a group of scholars from Miskatonic University on a previous expedition to Antarctica, during which they discovered ancient ruins and a dangerous secret beyond a range of mountains higher than the Himalayas.
A small advance group, led by Professor Lake, discovers the remains of fourteen prehistoric life-forms previously unknown to science, and also unidentifiable as either plants or animals.