Perito Moreno is a glacier located in Los Glaciares National Park in the southwestern province of Santa Cruz. It is one of the most famous tourist attractions in Argentine Patagonia. Its area is 250 km2 and has a length of 30 km. It is named after the explorer Francisco Moreno, who explored the region in the 19th century. One of the few glaciers that remains steady despite global warming is the Perito Moreno Glacier. The mouth of the glacier is 5 km wide and its average height is 74 m above the surface of Lake Argentino. The pressure from the weight of the ice slowly pushes the glacier across the inner fjord to the coast of the Peninsula de Magallanes and divides the lake into two parts. The water level in the part called Brazo Rico gradually rises and at irregular intervals the water pressure breaks the ice dam. The glacier advances between June and December and recedes between December and April.