The Perito Moreno Glacier is one of the classic Patagonian must-sees. It is a river of ice three miles wide, and towers 200 feet above the lake it empties into. The amazing thing is that the ice is also goes down another 350 feet below the water line!
But what's most impressive is that it is one of the few glaciers left in the world that are not retreating - in fact, it's advancing about a meter per day.
On a warm afternoon, the glacier is alive - groaning, creaking, cracking - and about every 10 minutes, chunks of ice that range in size from school buses to apartment buildings crash into the water and create mini tsunamis.
I took a boat cruise out to the face of the glacier for a closer view, but the best part of the day was just sitting on the observation deck and watching the ice chunks fall off into the water.
If you're wondering why the glacier is blue, it's because the pressure squeezes all the air out of the ice - it basically becomes a single, giant crystal. Ice absorbs red light, but lets blue pass through - hence the color. However, it usually takes at least 300 years for the ice to turn blue - so the older the ice, the bluer it becomes.
Zoom in on the map above to see the glacier - and check out the video to see a chunk about 100 feet high fall into the water.