Whirlpools & maelstroms are two terms for rotating bodies of water caused by colliding tides. Fictional whirlpools are often large enough to rip ships apart and drag them to the ocean’s bottom. They may be the reason for treacherous waters, and may be caused by leviathans, angry sea gods, or other creatures. These sites may have ruins, temples, shipwrecks, shipwreck towns or other sites at their center.