a frozen constantly moving and shifting network of passageways. >> scott: the walls come in, the ceiling comes down, the floor comes up. >> anthony: requiring constant maintenance. what's supporting this roof? >> scott: compaction of the snow. >> anthony: scott smith runs the crews keeping these tunnels clear and pipes flowing. >> scott: we're in the process of taking the chainsaw depth off the walls and ceiling to make them into a more usable entry. a lot of work. >> anthony: pretty amazing feat of engineering here. the lowest recorded temperature at the south pole is 117 degrees below zero. >> scott: where roughly at minus 59 right now. >> anthony: minus 59. >> scott: it's fahrenheit. >> anthony: wow, it only feels like minus 20. i can tell you it scorches the lungs and creeps through your heavy outerwear. >> scott: 200 ft below the ground, we've melted a giant enormous lake down there about 2 million gallons. this takes about 20 inches of snow to make an inch of water. pump that fresh water supply up to the station. it gets treated at the power plant. the rest comes back down