At the Mountains of Madness by Howard Lovecraft

The story details the events of a disastrous expedition to the Antarctic continent in September 1930, and what was 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.
The story is recalled in a first-person perspective by the geologist William Dyer, a professor at Arkham's Miskatonic University, in the hope 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. Six of the specimens have been badly damaged, while another eight have been preserved in pristine condition. The specimens' stratum places them far too early on the geologic time scale for the features of the specimens to have evolved. Some fossils of Cambrian age show signs of the use of tools to carve a specimen for food...
Famous works of the author Howard Phillips Lovecraft: At the Mountains of Madness, The Dreams in the Witch House, The Horror at Red Hook, The Shadow Out of Time, The Shadows over Innsmouth, The Alchemist, Reanimator, Ex Oblivione, Azathoth, The Call of Cthulhu, The Cats of Ulthar, The Dunwich Horror, The Doom that Came to Sarnath, The Festival, The Silver Key, The Other Gods, The Outsider, The Temple, The Picture in the House, The Shunned House, The Terrible Old Man, The Tomb, Dagon, From Beyond, What the Moon Brings.