This ‘Lost Land’ expedition took us into the wilds of Papua New Guinea and the relatively unexplored Mageni River Cave.  With the cave entrance effective 2/3 of the way up the side wall of a canyon and with our base camp on top of the rain forest plateau – the commute to work meant a heart stopping abseil through vertical jungle and drooling limestone to swing in to the cavern itself. Then as we looked down, out of the mouth of the cave spewed a 100m high waterfall that cascaded to the main river in the bottom of the canyon below.  Once inside, highly technical rope work and some extremely tense movement down unexplored sections of the system had us fuelled on adrenaline.