Sirens is an adventure map location, that can only be found from the sea. When a hero visits Sirens, 30% (rounded down) of each stack in hero's army will dive under water and perish. However, the hero gains experience equal to the health of the lost troops. A hero can only lose troops to Sirens once, no matter if there are more than one location where Sirens can be found. After the first visit to Sirens, the hero orders his troops to stop up their ears with wax, which prevents them from the effects of Sirens' songs.