A lot of times people will get to Costa Rica and are not sure what there is to do nearby. However, it looks like you are making a good decision by doing your research to see what there is available.
Let me just say, that there are numerous activities you can do in Costa Rica, but this is something I recommend for anyone simply because the vast majority of people have not done anything like this.
Since Costa Rica is known for its lush rain forest with howler monkeys, beautiful birds, and amazing plants, there are a couple of places around Costa Rica to do a canopy tour. Essentially, it is a zip line that will start you out up on a hill and go through the forest, following streams and things like this. As it feels like you are flying through the jungle, you will often see species that you have never seen before. We were graced with the opportunity to see a few howler monkeys within 10 or 15 yards away. They did not seem to mind us being in the area although they did howl a couple of times. It was a lot of fun!
The Mahogany Park canopy tour, also known as the Original Canopy Tour, is the one we visited. There were a few times throughout the day that they were accepting the tours. For this reason, I recommend calling them several days in advance and scheduling your group, especially if it is fairly large. You can schedule the tour for 7:30AM, 10:30AM, or 2:30PM. All of them have their perks, but it seems like animals like to be out more during the early morning hours, so I would recommend one of the two earlier times if you can swing it.
You should expect the tour to last quite a while. You will probably spend about two to two and a half hours going down the zip lines. Even though you are moving fairly fast the fear is typically far less than you would think after you do it one time. That first time I was considerably nervous. However, from then on you’ll be more stuck on what is around you as you are going through the jungle than your destination. In fact, there were several kids taking the tour when we went, some of which were pretty scared at first, but were fine by the time they had done it a couple of times. Just be expecting a lot of fun!