Volcanic mountains in the area equal lots of slopes, so the island offers some thrilling rides -- it is perfect for mountain biking. You can rent bikes from many of the hospedajes on the island, including Hotel Hacienda Merida. Comercial Arcia, 2 blocks south of Moyogalpa Church (no phone), also rents bikes, at a rate of C20 an hour.
The east coast of Maderas makes for a particularly good and challenging spin, and along the way, you can stop to see the cave paintings in Tichana and petroglyphs near Corazal. Make sure to get a good bike, as it is tough terrain.
Besides notching a volcanic peak or two into your belt, the island provides ample opportunities to go for a wander, happen upon ancient pre-Columbian relics, and admire the stunning sunsets. Just pick a path, but remember that much of what you walk upon is private property and, though the islanders in general have no problem with you traipsing across their lands, you should always ask for permission first. Most hotels and lodges have their own set of circuits and interesting things to see close by, one example being the petroglyphs of Finca Magdalena.
In many ways, horseback riding is the best way to get around this muddy, steep terrain. Indeed, I'm surprised no independent operator is offering rides yet. Ask at your hotel for what they offer regarding saddleback riding.
Reserva Charco Verde is a good spot for paddling. You can rent kayaks to take out there at the nearby Hospedaje Charcoe Verde (tel. 505/8887-9302) at hourly rates of C100 for a single and C150 for a double. Another great splash is along the coast north of Merida and up the Istián River. It can be tough going if you have the wind against you, but once you get on the river, it makes it all worthwhile. Another less-challenging kayak trip is to Isla el Congo south of Merida. Ask at your hotel about kayak rentals for the river Istián and Isla el Congo.
Climbing Ometepe's Volcanoes
You don't often get the opportunity to stand beside a lake within a volcano, but you can do so in Isla de Ometepe. However, such bragging rights don't come easy. Volcán Maderas may be the smaller of the two volcanoes here, at 1,394m (4,573 ft.), and the most frequently hiked, but it is not easy going. Getting there involves an all-day hike up a steep incline, passing coffee plantations and the occasional pre-Columbian carved stone along the way, and down into its inner rim. This last part requires ropes, so it is imperative that you go with a reputable, fully equipped guide. People who attempt the volcanoes alone can end up lost, injured, or dead. There are two ways of approaching the peak, either through the grounds of Finca Magdalena near Balgue (they charge a small fee if you are not a guest) or from the other side at Merida. Hotel Hacienda Merida arranges excursions in which trekkers descend at Finca Magdalena and are transported back to the hotel.
Volcán Concepción is the big one -- a perfectly formed cone 1,610m (5,282 ft.) high. It's a long and arduous 10 hours up and down, and a different experience from Maderas in the sense that you're walking on a live volcano that could erupt at any time. The last time it rattled its bowels was in 1957, and it has done so four times in the past 100 years. Do the math: It is due for another eruption soon. A thick jungle forest of monkeys and birds gives way to rocks and shale the higher you go here. A stiff wind helps or hinders you along until suddenly the hot sulfurous belch blasts upward from the crater as you reach the rim. This is what forms the almost permanent cloud that clings to the peak. If you're lucky and come on a clear day, you'll be rewarded with the sight of the volcano's chilling stony interior and spectacular views of the island -- you'll want to linger and take in its otherworldly atmosphere. La Sabana is the best place to start your climb to Concepción. You can also approach the volcano from a trail behind Altagracia. You must go with a guide, even if you just want to explore the lower reaches, as it's very easy to get lost.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.