Magnificent birds including many kinds of hummingbirds, the famous resplendent Quetzal, parrots, and many more. Also the agouti and coati. The forest itself is very interesting.
You must have a guide though to really get something out of the experience.

Wonderful place and excellent guide! So much to learn and see. The waterfall was beautiful, as was the forest, but the topper was getting to see three of the legendary Resplendent Quedzal birds, an amazingly beautiful bird I will never forget.

First, make sure you get your entrance ticket from the "Registration" building. You cannot get tickets at the actual entrance to the trails. The trails are well-marked and match the trail map. They also have great overview map signs throughout the park at trail intersections in case you don't want to keep pulling out your map. We got here just as it started to rain and we ended up hiking in torrential rain in December (the dry season?). The trails got really muddy so make sure you have hiking boots and rain gear with you or you'll regret it. Our 2 1/2 yr old son had a ball checking out all the cool tropical vegetation. He was in a backpack carrier as the trails were too muddy and treacherous for a toddler due to the rain. Though we weren't able to see many birds because of the downpour, we did enjoy the trails and the suspension bridge. The bathrooms were clean.

The gift shop was okay and had some nice laminated bird, plant, and mammal guides as well as a decent assortment of t-shirts and gifts. Others in our group said the cafe next door had a decent sandwich selection for a quick bite and enjoyed the coffee.

We parked across from the Hummingbird Gallery and had to stop in on the way back. This was one of the highlights of the trip. The rain had finally stopped and we saw a kinkajou visiting one of the hummingbird feeders! Everyone really enjoyed standing quietly near feeders with 50-60 hummingbirds of multiple species buzzing around your head. Our toddler son was fascinated and didn't want to leave. They also have a nice gallery/gift shop.

We did a couple of trails on our own and had a fantastic time. There were tons of people at the entrance when we arrived around 10:30 a.m., but we saw no more than a dozen people once we started hiking.

If you make it to the lookout point and the skies are clear, you're in for a treat. Beware: close to the lookout point, these little bugs flocked to us and started to bite.

The trails are well marked and the staff at the reserve are very nice.

We had lunch at the cafeteria and the casados were quite delicious and of healthy portions.