The youngest volcano in Costa Rica is also the most active. Presumed extinct until a destructive eruption in 1968, Arenal has been active ever since, but with much less ferocity. The spectacular pictures found on postcards were likely snapped during the last major eruption of August 2000. Clouds usually cover the tip. Especially when the afternoon rainstorms roll in, making morning the best time for viewing. Lava is generally not visible from the city of La Fortuna. Getting up to the volcano for a night viewing is easy with a tour or visit to the hot springs, but an eruption is not guaranteed. Many visitors miss the lava if it occurs late during the night. Staying at one of the hotels along the road out of town affords a view of the volcano all night long. I was fortunate during my visit to see, from town, red rocks shooting up after the clouds cleared from a major thunderstorm. While soaking in the hot springs, rocks broke up and lava flowed down the side. Tour operators offer several options to experience the area. Afternoon hikes or horseback rides through the lush rain forest with an experienced guide are a great way to spot animals and flowers. Relaxing at several hot springs is an entertaining way to wait for the lava. Budget travelers can find $10 night tours from town, but remember lava sightings are not guaranteed.
During the rainy season, afternoon thunderstorms are common and strong. Take rain gear for hikes and dry clothes in a waterproof bag for after a soak in the hot springs.
Locals can provide an informative history of the area. Only consulting the dictionary once, I learned all about Arenal from a worker at the hostel. He told me that a few years ago rumbles were felt in town and they have evacuated 3 times in the past, but right now "she is not a menace, she is our friend".