Everything you need to understand or teach The Land That Time Forgot by Edgar Rice Burroughs.
Many literary critics regard The Land That Time Forgot as Burroughs's best work. The book's three novellas—"The Land That Time Forgot," "The People That Time Forgot," and "Out of Time's Abyss"—tell the stories of three different men who become trapped in the strange land of Caspak, which is filled with voracious carnivores and hostile primitive tribesmen. Each novella is a tale of high adventure and suspense played out against the backdrop of an intricately developed fantasy world.
Many elements are standard fare for a Burroughs adventure. Coincidences appear frequently, whenever the plot is in danger of hitting a snag, and romantic entanglements—frequently between people of different cultural backgrounds—also add spark to the plot.