I've visited Costa Rica 7 times and have never been able to find a Sloth. Walking into my favorite restaurant on the way to Manuel Antonio National Park I find a Sloth and her baby in a tree right by the entrance.
We could have paid for a tour to see the Falls, the Chocolate Lady and the town of Bribri. But heck, we're adventurers. We set out in the Jeep for a 5 hour adventure to the Panamanian border, only to learn the falls were fifteen minutes outside of our Village of Puerto Viejo.