The Panama Canal Zone, next to Panama City, Panama, including the areas around Gamboa is one of the best areas for ecotourism in all of Panama. You can choose between nature or cultural ecotourism.
For cultural ecotourism, I recommend the Embera indigenous communities that live on the banks of the River Chagres. The tours are managed by the Emberas, which gives them a chance to create and manage their own source of income.
There is also nature-related ecotourism in the Panama Canal Zone, whether you are into fishing, kayaking, swimming, hiking or just plain sightseeing, as the video shows.