After searching thru Nova Aetas discussions, I haven't found any keys for the hidden treasures. These treasures are a chests with a loot inside (as that chest with samurai outfit in vanilla Warband), and they're hidden in a city ruins. Just found by myself a chest with silk, war darts and smth else, while searching an Uxkhal ruins.

So I was wondering, did somebody found all the treasures and, maybe can help me with it? It's taking a lot of time to wander around a location just to find something not worthy your searches.