Perito Moreno Glacier
In addition to its enormous beauty, it is the planet's 3rd largest reserve of fresh water and one of the continent's last advancing glaciers. It slowly pours, in crackling celestial blue, from the granite spires of the Chilean Paine Mountains into Argentina's Los Glaciares National Park.
The glacier is a kinetic attraction, emitting sonic booms as it calves icebergs the size of skyscrapers into placid Lago Argenito. Every decade or two, it extends its reach just a tad too far, forming graceful ice bridges and tunnels just a bit too thin to hold, and the entire structure collapses into the sea, creating an ice flow of epic proportions.
While many visitors stay on solid ground, more adventurous travellers can explore the inlet in small boats, or even don crampons.