Edgar Rice Burroughs 
Tarzan and the City of Gold [EPUB ebook] 

In the fabled land of Onthar lie the twin cities of Cathne and Athne – one a city of gold, the other a city of ivory. For generations the Cathneans and Athneans have warred with one another, using armies of trained lions and elephants. When Tarzan rescues Valthor, an Athnean, the Ape Man is taken captive by Nemone, the mad Queen of Cathne – as a pawn to be used in the savage "games" conducted for her amusement.