There is speculation that it could be the White City. A legendary lost city whose ivory temples were filled with treasures.
Or perhaps, its the lost city of the Monkey God. A tale circulates among natives about a city where giant apes were worshipped. There a mountainous temple was constructed with a giant simian as its central figure. The story of the Monkey God came to light in 1939 when Theordore Morde wrote about it after one of his many expedition to the region. He spoke of a people half man, half ape, who worshipped Monkey God.
We'll never know of course because Morde mysteriously died in 1954. Some say it was suicide, others, the curse of the Monkey God.
Sounds like a region ripe for adventure!