Kitab al Kanuz (sometimes called The Book of Hidden Pearls) was a mysterious medieval Arabic manuscript from the 15th century, supposedly a treasure hunter's guide noted for its mention of the Zerzuraoasis. The author is unknown as well as the exact date of the manuscript's existence, but it is certain that it first appeared in the 15th century.
The Kitab al Kanuz is a collection of mystic fables and lists over four hundred sites in Egypt that hold hidden treasure. It also details the many spells and incantations needed to ward off supposed evil spirits who guard the treasures. However, the manuscript is known mostly for its mention of the Zerzura oasis actually being a white city full of treasure with a sleeping king and queen and which was threatened by black giants who would emerge from the desert and attack oases in Egypt, The guide instructs the treasure hunter to take the key to the city from the mouth of a bird carved into the wall above the gates, unlock them, and take the king's and queen's riches without approaching them.
It is difficult to know if the Kitab al Kanuz still exists or whether it has become an anitiquity in a museum or not, though archaeologists and explorers seem to be well-acquainted with it. E.A. Johnson Pasha, a member of the Royal Geographical Society in the 20th century, claimed to have had the manuscript in his possession for several years in the 19th century through 20th century [jstor.org/stable/1783755]. Austrian count Ladislaus Almasy also read the manuscript and became enchanted by its Zerzura tale, which inspired him to help British explorers make expeditions into the Sahara desert for the Zerzura oasis in the 1930s.