One Of Costa Rica's Most Scenic Lakes Sits Beneath A Massive Volcano With Hot Springs And Wildlife-Filled Trails

Costa Rica earns its reputation as a biodiversity hotspot with jaguars and toucans hiding in the cool mists of cloud forests, a plethora of beaches where endangered green sea turtles nest, and the kaleidoscope of marine life swirling around its coral reefs. In this Central American gem, you can relax in an aquamarine swimming hole surrounded by smooth, grey boulders, or find yourself at eye level with monkeys at the country's first rainforest tree-climbing park.

For a different kind of adventure, head to Lake Arenal in the country's northern highlands. Located at the foot of a massive volcano, the lake is the country's largest — long and thin, it covers 33 square miles. The volcanic activity in the area results in natural hot springs for visitors to enjoy, and the lake is ringed by wildlife-filled trails. There are many ways to experience this spectacular spot, ranging from active adventures like zip lining and windsurfing to more easygoing ones like watching a memorable sunset on a cruise or relaxing at a nearby five-star resort.

Lake Arenal is 60 miles from Liberia Guanacaste Airport and roughly 120 miles from Juan Santamaría International Airport in the capital of San José, which is about two-and-a-half hours away. The country's roads can be challenging, with rain washouts and potholes being a prevalent occurrence, and public buses being somewhat unreliable. It's a good idea to book either a shuttle, ride-share service, or a guided tour from San José.

Swimming is one of the best things to do at Lake Arenal, but keep in mind there are no designated swimming areas or lifeguards on duty. Windsurfers also come from all corners of the Earth in the dry season (which runs from December to March) when reliable, strong winds propel them across the lake. Anglers will be happy to know that the lake is full of tilapia and rainbow bass, drawing fishing enthusiasts to numerous lakeside outfitters to help them land a catch. 

Kayaking and jet skiing are also popular activities here, and boat tours give visitors a chance to spot wildlife — including boa constrictors, caimans, and iguanas — from afar. The western side of the lake is where windsurfers and kitesurfers find the strongest winds, and the eastern side's calmer conditions invite more serene experiences like paddle boarding and sunset dinner cruises. 

Besides being famously picturesque and a destination for all manner of water-based activities, Lake Arenal has a fascinating history. Until construction finished on a nearby hydroelectric dam that was constructed in the 1970s, the lake was three times smaller than it is today. Two abandoned cities now sit at the bottom of the lake, their inhabitants having moved before the area was flooded.

The conical, postcard-perfect Arenal Volcano rises 5,358 feet above the lake and is surrounded by the 30,000-acre Arenal Volcano National Park. The volcano, which last erupted in 2010, has a 460-foot-wide crater, miles of trails, cascading waterfalls, and a series of footbridges. The treetop view from tour company Mistico Park's hanging bridges allows visitors a chance to connect with nature, offering possible sightings of three-toed sloths, howler monkeys, coatis, and stunning tropical birds. The area is part of a protected wildlife route called the Monteverde–Arenal Bioregion, which connects the Monteverde Cloud Forest Reserve to Arenal Volcano National Park. 

More than 350 bird species have been spotted in the national park, from parrots to kingfishers. Thrill seekers will want to zoom over the tropical canopy on a zip line, and all will appreciate an end-of-day soak in a hot spring, geothermally heated from a subterranean reservoir. Horseback riding, river rafting, and mountain biking are other ways to explore the Arenal area. 

For a swimming adventure, head east from Lake Arenal to the town of La Fortuna, where you can take a dip in a secret swimming hole with a rope swing and swim in the crystal clear pool of a rainforest waterfall. Two top-rated places to stay in La Fortuna are the Nayara Springs Resort and Spa and the luxurious Amor Arenal (both will cost you around $700 per night). A more modestly priced stay is the Arenal Observatory Lodge and Trails, which charges around $100 per night. Don't forget your binoculars, camera, bathing suit, bug spray, sunscreen, light rain jacket, and hiking boots!