We did the Tongariro Alpine Crossing today in 7.5 hours ... 19.4 km between two volcano craters.  Thank goodness for my toque and gloves, the temp was -2 to start with 50 km winds.  Once we reached the other side, we entered a tropical paradise with +20 temps ... unbelievable terrain diversity.  We also made a little detour to see a very large carrot in Ohakune on our way to Wanganui.