It is the second in extension of the Icefields regions. Has a surface of 4.200 km2, their long one is of 100 kilometers among the Circus (46º30’S) and Steffen (47º40’S) glaciers, while their width reaches 45 kilometers among the glaciers San Rafael and Lions. The cord Aysén located in half of the plateau has a northwest-southeast address, being their biggest summit the Arenales volcano of 3.365 m.s.n.m.

In the most southern sector is the highest Mount in the Patagonia, the San Valentin whose englaciated summit the 3.970 m.s.n.m reaches. Also, of the Nothern Icefield descends the glacier San Rafael that is with its glacier front of 1.800 meters is considered as the ice mass that arrives to the sea, nearer to the Ecuador.