Expedition to the bottom of the world
S2, E6: If Troy Watson and Kieran McKay can connect New Zealand's Nettlebed and Stormy Pot systems, the find will be the biggest cave in the southern hemisphere.

S2, E6: If Troy Watson and Kieran McKay can connect New Zealand's Nettlebed and Stormy Pot systems, the find will be the biggest cave in the southern hemisphere.