Short answers, pulled from the story.
Sir Arthur Conan Doyle wrote the novel The Lost World published in 1912. Doyle created the character Professor George Edward Challenger and later impersonated him in a photograph for the novel's frontispiece.
The plateau named Maple White Land is located in what is now Bolivia. It is a remote tableland isolated by impenetrable cliffs and hidden from the modern world.
The explorers encountered dinosaurs including Iguanodons, a Stegosaurus, and pterodactyls on the plateau. They also faced a tribe of ape-men and a race of indigenous Accala Indians.
The four explorers were Professor George Edward Challenger, Professor Summerlee, Lord John Roxton, and Edward Malone. Malone was a young reporter who sought to win the heart of Gladys Hungerton.
Professor Challenger was inspired by the zoologist Ray Lankester and Edward Malone was modeled on the journalist E. D. Morel and the diplomat Roger Casement. Lord John Roxton was based on the explorer Percy Fawcett who organized expeditions to the Huanchaca Plateau in Bolivia.
The silent motion picture version of The Lost World was released in 1925. This film introduced the story to a wider audience and boosted the novel's popularity.