From Cañas to Tilarán and 7 kilometres from Tilarán starts the World of Arenal Lagoon.
In the center of green hills and cultivated fields invites the Arenal Lagoon to waterski, fish hike or boat. To the east towers the massive Arenal Volcano, which has been active since 1968. Appoximatley 2-3 million years ago there was no lagoon. However a tectonic movement depressed part of the terrain, forming a trench. In 1973 a dam at Sangregado raised the level of the lagoon to 540 meters above sea level enlarging it to 7,500 hectares. The building of the dam and the higher water level made it necessary to move several large towns (Arenal, Tronadora and others) as the ranches, pastures and cultivated fields werde flooded.
A trip to Arenal Lagoon can be rounded off with excursions to the lovely and rainy region of Lake Cote, apparently an ancient volcanic crater located 35 kms from Tilarán, or to the mysterious Venado Caves 50 kms away.