Introduction to Arenal Lake: Arenal Lake is located at the foot of Arenalgo Volcano, covering an area of ​​nearly 85 square kilometers and a depth of 60 meters. It is the largest inland lake in Costa Rica. In 1979, due to the construction of a hydropower station, its water surface area tripled. Today, the Arenal Lake Hydropower Station provides nearly 12% of Costa Rica’s electricity.