|Sirens as seen on the adventure map
Sirens is an adventure map location, that can only be found from the sea. When a hero visits Sirens, 30% (rounded up) of each stack in hero's army will dive under water and perish (one-creature stacks are not affected). However, the hero gains experience equal to the health of the lost troops (with bonuses of Learning secondary skill). 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.
Bug: can be re-visited after a battle (fixed in Horn of the Abyss).