Carlos was extremely informative. We went on a bird watching hike in Monteverde, and we spent an amazing 3 hours in the park. Carlos was extremely patient to answer all our questions and pointed to us various kinds of birds, where to find them etc. We sometimes spent 15 minutes in taking a picture of a rare bird. The zipline in the afternoon was also quite fun that I'd definintely recommend. Carlos also made some recommendations for the rest of our itinerary in Costa Rica.