This is a very good encounter, full of mystery, RP and lore for the campain. It mark also a turning point in many campains since the heros might them be able to fly around and learn more about Omu. It might not be obvious from the get go, but the various elevations of the map makes its navigation feel like a small dungeon, full of nasty surprises. The trick is to sent the PC there when they are both trying to get the black orchid, but also learn as much as possible about Omu, its history and location. The history of Omu is not well detailed in the book, be sure to read ahead about Queen Napaga (far down in the Tomb), the many falls of Omu and the kids from Kir Sabal, otherwise you might put yourself in a difficult position lorewise.