Top 2 in Top 15 best volcanic climbing places in the world.
Discovery of Arenal Volcano
Arenal was one of the most active volcanoes from about 1968 to 2010, since then activity has slowed but it still spews ash and sometimes lava. It has a classic shape, tall and quite proportional. You can't climb to the top of this volcano because it's illegal and very dangerous, but luckily there are a few worthwhile hikes that are perfectly legal and still get you up to Arenal. Inside the Arenal Volcanic National Park, with a length of about 5 km, will take you through the rainforest, you will have the opportunity to see the peak of the mountain. A lot of wildlife that you can observe includes Toucan birds (members of the family Ramphastidae include finches from the Neotropics) and monkeys. Walking through the old lava flows, you can also hear the "breathing" of the volcano, which is actually quite impressive.