Arenal Volcano

The Arenal Volcano, in Spanish Volcán Arenal, is an active andesitic stratovolcano in north-western Costa Rica, around 90 km north-west of San José, in the province of Alajuela, canton of San Carlos, and district of La Fortuna. Recognized as a volcano since the 19th century, it was known by foreign investigators as Volcan Costa Rica, Rio Frio, Canastos Volcano and Cerro de los Guatusos. Arenal is the youngest and most active of all the mountains in Costa Rica. Scientists have been able to date it back to more than 4000 years ago. The area remained largely unexplored until 1937, when a documented expedition took place to reach the summit.

What I like the most when it comes to volcanoes is when they erupt. On nights, you can see the red lava flowing down the hill.