Rincon de la Vieja, loosely translated, means “the hideaway of the old lady.” No one we asked knew how the volcano got its name. Despite the park’s rank as Guanacaste’s number-one attraction, we didn’t pass many others on our hike. With 34,800 acres, there’s plenty of room to explore.

Again, we recommend hiring a guide. Not only do these naturalists know where they are going, but they also know what they are seeing. Along the easy 1.75-mile Las Pailas loop, our guide pointed out guanacaste and poisonous jabillo trees, led us to a waterfall and explained that the whistling cry we heard belonged to a trogan. On spurs off the trail, we viewed bubbling mud pots and fumaroles belching sulfur. In a clearing, we caught sight of a flock of wild parakeets, and we paused as a troop of white-faced capuchin monkeys jumped around above our heads.

With hardy teens, consider a guided five-mile trek to the summit.