Arthurs Pass Railway Station. Arthurs Pass is named after Sir Arthur Dudley Dobson and is now contained within the Arthurs Pass National Park. After the Arthurs Pass Station, the train enters the 8500 metre Otira Tunnel descending 250 metres over the length of the tunnel (the area traversed can bee seen on here on map.google.com). After the train enters the tunnel, a large door closes over the entrance and large fans begin extracting the exhaust gasses. The viewing carriage is off limits until we reach breathable air on the other side.
I should have tried fill-in-flash here. In haste I used ISO200 - which was far too noisy, but Noise Ninja has fixed some of this.