The main attraction of El Calafate is the the Perito Moreno Glacier which is located in the Los Glacieres National Park, 80km west of the small tourist town.
There are 48 glaciers in the Southern Patagonian ice-field. The Perito Moreno Glacier is particularly special because it is one of only three of these glaciers which are not retreating. Instead it advances up to 2 meters each day, and whilst doing so it continually cracks and moans until a piece breaks off and comes crashing down into the water with a thunderous roar.
The front of the glacier is 5 kilometers wide. It has an average height of 60 meters above the water and it extends back as far as the eye can see (n.b. "as far as the eye can see" is 30 km).
Whether it is a small chunk or an entire face of the glacier, the finale is always a loud, roaring vibration through the air as the piece disintegrates in the water below or goes on to become a miniature iceberg.