Ypacarai Lake

Ypacaraí Lake is a major body of water located in Paraguay, about 50 kilometres east of the capital, Asunción. The lake lies in the western part of the Asunción-Sapucai-Villarrica graben, a tectonic depression from the Mesozoic Era, and drains to the northwest through the Salado River into the Paraguay River. It is surrounded by three cities: Areguá, Ypacaraí, and San Bernardino, the last two being located on its shore. It is one of Paraguay's two main lakes, providing water for drinking and irrigation, and is also the site of many leisure activities.

As a result of the proliferation of toxic algae or cyanobacteria, as well as nearby livestock farms, residential areas, large-scale deforestation, and land development, the lake is the most polluted in Paraguay. Due to the contamination, the lake has turned green and swimming in the lake is not advised.