Start your day off with a visit to Arenal Volcano National Park, La Fortuna's most popular natural attraction. Hike one of the park’s large network of trails, with options suitable for all levels of hiking, then take a refreshing dip in the pools at the base of 200-foot-high (61-meter-high) La Fortuna Waterfall, just outside the park.

In the afternoon, head to Proyecto Asis, a wildlife-rehabilitation center that cares for injured or orphaned animals with the goal of eventual release back into the wild. Here you might see animals such as spider monkeys, peccaries, and caimans, and even volunteer to lend a helping hand.

As night begins to fall, make your way to Mistico Arenal Hanging Bridges Park, just west of town. This park features 16 hanging bridges that weave through and above the rain forest, affording great views and the opportunity to spot wildlife; guided night visits are particularly interesting for those who want to see nocturnal animals at their most active.

Spend your second day in La Fortuna taking advantage of the area’s myriad opportunities for outdoor activity. Multiple zipline options are available, most of which offer exhilarating, multiline adventure packages that give travelers the chance to soar high above the rain forest.

In the afternoon, head out for some white-water rafting, led by a local guide. Most area rafting packages are suitable for guests of all experience levels; while the rapids are the main draw for most travelers, you'll likely also get the chance to spot all sorts of wildlife as you make your way along the river. Some tour packages pair rafting with ziplining or canyoning.

Wrap up your stay in La Fortuna with a relaxing soak at Tabacon Hot Springs. While many visitors opt to spend the day at this upscale resort, it’s a great place to visit after nightfall, when it’s well-lit but less crowded.