Nothing is quite as pure as freshly fallen snow.
If you are really adventurous you can travel inside the glaciers of Iceland and get an up close look at how they are made. The darker layers are the snow that falls and is compacted by more snow. The lighter layer is the melt water that runs when the snow melts. When it cools back down that melt water freezes into a layer of ice.
Iceland is far for most people to travel to and it is expensive when you get there (meals averaging 40$-50$ per person) but I recommend it to anyone and everyone.