With an area of 370 square kilometers (142 square miles), Lake Valencia, in northern Venezuela, formed a few million years ago and is now a reservoir for the nearby cities of Valencia and Maracay. Unfortunately the inflow of untreated wastewater from the surrounding industrial and agricultural lands has led the lake to become contaminated. It now suffers from algal blooms and between 1960 and 1990 lost more than 60 percent of its native fish species. The poor-quality waters of Lake Valencia prevent the development of tourism and recreational activities in the region. In this false-color image Henri Pittier National Park, to the north, appears fluorescent green. February 2, 2019.