Dominated by the conical cone of the volcano, Arenal National Park covers an expanse of 12,124 ha. Upgraded from a reserve to a national park in 1994, the park protects the valuable watershed that maintains water levels in Lake Arenal and the microclimate created by the volcano.
Trips to see the lava flows and eruptions of Arenal Volcano, when active, are always popular. While there are variations on a theme, most leave in the late afternoon to get you to the best viewing spot for dusk. As darkness cloaks the region, the barely visible dust plumes that skirted down the bare slopes through the day reveal themselves to be glowing lava tumbling, crashing and smashing down the volcano slopes in a spray of natural fireworks. When the volcano is active and the night is clear the sight is spectacular and the sound decidedly eerie in the dark of night.