There are many glaciers in this region, but the two most famous are Fox and Franz Josef. Franz Josef is about 20km from the sea and right now is moving rapidly (in glacial terms) at approx a meter a day. Most move only centimeters in a year. It is dependent on the snowfall over the preceding 10 years or snow that packs new snow on the top and pushes down on the base. The other unusual aspect is that the glacier is plowing through a rain forest. I took a walk this afternoon to the base of the glacier, or as close as they will let you go unescorted. There is a car park and then a short walk in the rain forest and the path winds around and then suddenly you make a right turn and you are looking at the glacier about 2 km away. The weather changes rapidly and the valley is steep sided so you can feel the cold air coming off the ice the closer you get. Basically you walk up the riverbed that is very rocky but with a decent path and markers and you get within about 500meters of the base. There is a constant danger of icefalls and some of rock falls and slides.
So called "Victoria Falls" The water coming out of the base of the glacier
They have full day and half day guided tours and also helitours where you are taken on to the glacier in a helicopter and hike for about 2 hours and then taken back down. There are also aerial tours with a glacier landing, which is what I chose after some deliberation. I actually did this first based on the availability of seats. I think it was a Bell Jet Ranger and seated 6 plus the pilot. The heliport is about 300 meters from the hostel (as is everything else in town) and you can hear them going and coming constantly. When we landed on the glacier there were five others there at the same time from different operators.
The ride up is dramatic as you pass close to the sides of the valley and then fly over the ice field, and then over the ridge where it becomes Fox Glacier rather than Franz Josef.
Banking through the valley following the glacier