Arenal Volcano national park encompasses the impressive conical peak and surrounding lava fields as well as the extinct Cerro Chato and the lagoon in it’s crater. There are a number of trails and it would be possible to hike from the ranger’s station on the northern flank around to the west then south past the Observatory Lodge up to the crater of Chato, around the rim and down to La Fortuna waterfall and the village.
Although we’ve hiked the segments we’ve never put it all together. Sometime when we want an all day expedition we’re going to give it a shot.
The trails from the ranger station are mostly through cane and across regenerating lava flows. If you want to see the rainforests you’ll either need to continue all the way to the end and pick up the Tucanes trail (walking at first then easy to medium hiking) or start from Catarata Fortuna and climb the slopes of Cerro Chato to its crater where you get some of the best views of Arenal and can take a dip in the cool green lake a the top (steep and challenging but short hike). The differences between walking and hiking are explained on this link.
There are a few photos from the good old days with massive lava explosions but Arenal has been very quite for the last seven years or so and we’ve concentrated on photos of what you might see if you visited today.