Pressure loving organisms that live either at the bottom of the sea or in the
deep hot biosphere. Since water
pressure roughly doubles every 10 meters, the deep trenches of the
ocean are many atmospheres more pressured than us. If this simple calculation were true then two Km deep would be 1 millon or more times atmospheric. Probably, it's less than that but anything that lives that
deep has to be pretty tough.
See : extremophile