Answer for 10 days Cahuita and ???

Hi Karen,
You’ll get in some good beach time in Cahuita so maybe head to the mountains (Arenal or Monteverde) for the other part of your trip since it will have a very different feel. Between the two, both are great destinations, but with 4 days, we’d say Arenal is probably your best bet because it has more to do, especially based on your list (it has rafting, hanging bridges, good hiking, etc.). Here’s a blog post we did with more info about what the area is like, hotels, etc.: La Fortuna: What to Expect from Costa Rica’s Most Popular Destination. We also have a post about Monteverde if you’re still not sure: Monteverde: A Forest in the Clouds.
Hope that helps!