Among the lakes in Parque Nacional Los Glaciares is Lago Argentina, the largest lake in Argentina, 15,000 years old. Lago Viedma, and Lago Argentina flow into the río Santa Cruz which runs east into the Atlantic. Glaciar Upsala is the largest glacier in South America. It is 37 miles (60 km) long and 6 miles (10km) long. You can reach it only by boat, playing dodge'em with the icebergs, or ice islands, floating in in Lago Argentina.
Feeding Lago Argentina is the Perito Moreno glacier in the enclosed Parque Nacional Perito Moreno.
Perito Moreno is about 60 m tall and every so often, about every four years, portions will break off into the Canal de los Tempanos, or Iceberg Channel, in a huge explosion of ice and water. This is a tremendous display, but visitors enjoy the glacier at any time of year.