A 2020 photo taken from space captures a striking natural feature in Patagonia, where two glacial lakes of different colors meet. The lakes, Lake Pueyrredón in Argentina and the Chilean Lake Cochrane (not visible in the photo), were once a single body of water but were divided by a narrow land bridge. Both lakes are deep and clear, with Pueyrredón appearing as a deep blue from above due to its depth of up to 1,600 feet (500 meters). Thousands of years ago, a thick layer of sediment formed across the southern part of Lake Pueyrredón, creating a new, smaller lake called Lake Posadas. This smaller lake, about 5 miles (8 kilometers) long, has a lighter, teal color because it is shallower and receives a large amount of sediment from a nearby river. Additionally, other rivers from surrounding hills have deposited sediment along the western shore of Lake Pueyrredón, forming three fan-shaped landforms known as deltas, which increase in size from north to south. Wind-driven currents and waves have moved some of this sediment from the edges of the deltas, forming long, thin strips of land called sandspits that point in the direction of the current. The land separating Lake Pueyrredón and Lake Posadas resembles these sandspits but is likely a moraine—a ridge of sediment and rocks left by a glacier or iceberg. The area is not entirely uninhabited and attracts tourists who enjoy activities like camping, hiking, fishing, and kayaking. Lake Posadas is also notable for a unique island with a massive rocky arch, a popular attraction. Both lakes lie within a large valley carved by a massive ice sheet that once covered the region. The last remnants of this ice sheet are found in northern Patagonia, near Lake Cochrane, and have also been captured in space images. Patagonia is known for many similar valleys and fjords formed by the same ancient ice sheet. About 210 miles (340 kilometers) southwest of Pueyrredón and Posadas, a rare natural configuration occurs where a lake, river, and glacier meet at a single point.