"Tarzan and the Forbidden City" is a novel by Edgar Rice Burroughs, the twentieth in his series featuring the jungle hero Tarzan. Published in 1938, this adventure takes readers to a mysterious African city, hidden and uncharted, called Ashair. The city is home to a fabled diamond of enormous value, which becomes the object of various characters' desires. Tarzan finds himself embroiled in the quest when he agrees to search for Brian Gregory, a man who disappeared while looking for the city and the diamond. Accompanied by Brian's sister, Tarzan encounters treacherous landscapes, fierce animals, and hostile natives. The city itself is rife with intrigue and danger, its society characterized by strange customs and the worship of a sacred oracle. Burroughs' narrative is rich with action and exotic imagery, as Tarzan's prowess and wilderness wisdom are once again put to the test in this timeless tale of adventure, valor, and discovery in the heart of Africa.