Who guides you
A Monteverde family business built around guides who never stopped learning the forest
Nasua Tours is run from Monteverde, Puntarenas, by Oscar Castillo Mejía Mejía — professional bilingual naturalist guide and co-owner — together with a team of certified naturalist guides experienced in birding, night walks and natural history.
Oscar Castillo Mejía Mejía
Oscar is a professional bilingual naturalist guide certified in Costa Rica, carrying guide license #1090, with almost twenty years of experience interpreting the flora and fauna of the Monteverde region.
What that means in practice is local, seasonal knowledge: which trees are fruiting this month, where a Bellbird has been calling, which reserve better matches your target species and expectations, and how to set a scope on a bird so everyone in the group actually sees it — not just the person holding the binoculars.
Every tour is customised. Your guide adapts pace, distance and depth of explanation to who is in front of them, whether that is a dedicated birder chasing a list, a family with young children, or a couple on their first cloud-forest walk. That is why most of our experiences are offered privately.
The company is named after the nasua — the coati, the curious, sociable, endlessly investigative mammal you often meet along Monteverde trails. It felt like the right symbol for the way we like to explore.
Today Nasua Tours is more than one guide: our certified naturalist guides share the same standards of interpretation, optics and small-group attention, with Oscar as founder and lead guide.
License #1090
Certified bilingual naturalist guide in Costa Rica.
Almost 20 years
Guiding in and around the Monteverde cloud forest.
Local to Monteverde
Curi-Cancha, Monteverde Cloud Forest Reserve and the Wildlife Refuge.
4.9/5 from 814 Tripadvisor reviews · 5.0/5 on Google (295 reviews)
Travellers consistently highlight patient, knowledgeable guiding.
How we guide
Small and personal
Private tours by default, so the walk follows your interests, your pace and your questions.
Interpretation, not a checklist
We explain how species, trees and weather in the cloud forest are connected, rather than only naming what passes by.
Right place, right hour
Reserve, route and start time are chosen for what you want to see — early birding, mid-morning natural history, or dusk.
Ready to plan?
Start with the Monteverde planning guide if you are still deciding between private birdwatching, a nature walk and the night walk, or write to us directly at info@nasuatours.com.
Photographs from our guided walks
Every photo on this site was taken by our guides in and around Monteverde — no stock imagery.
Nasua Tours naturalist guide explaining cloud-forest ecology to a small group 
Birders scanning the canopy with binoculars at dawn in Curi-Cancha Reserve Naturalist guide carrying a spotting scope along a misty Monteverde birding trail 
Guest looking through a spotting scope at wildlife on a Monteverde trail 
Night walk group with flashlights on a forest trail in the Monteverde Wildlife Refuge 
Eyelash viper coiled on a leaf, found during a guided Monteverde night walk 
Side-striped palm pit viper resting on night-time vegetation in Monteverde 
Katydid on a wet leaf photographed during a Monteverde night walk 
Leaf-mimicking insect camouflaged against the forest floor at night Pizote, the local name for coati, moving through the undergrowth at dusk