The Only Liquid Sulfur Lakes on Earth!

There are 112 active or inactive volcanoes in Costa Rica, but Poas, 2,700 m (9,000 ft) tall, is extremely unusual. It is not the most active (this being Arenal, 1,500 m/5,000 ft tall) nor the tallest (this being Irazu, 3,400 m/11,330 ft tall), but it has two craters: an active one, ... [ read more >> ]