Volcanoes and geysers are mostly uncommon, intermittent phenomena. Some volcano craters do stay pretty hot, for extended periods, though - it's true.

I'm not sure about how to measure the rate of entropy dissipation within the Earth - but I'm not sure it radiates as much heat from the surface as ultimately comes from the sun.

The insides of nuclear reactors, and other power plants are probably the most entropic places of all - again, per unit area. Whether those count as "environments" could be debated.