Dominica is famous for its rainforest hikes in the mountains and along cool or hot streams. The Boiling Lake hike is a three+ hour climb of 2355 feet along a muddy and slippery path over rocks and logs, and the return trip can be just as treacherous. The payoff is a large crater where sulfurous hot water boils up in the center. Having made this hike in the past, I deferred from joining our group, which started at noon and returned after dark, with no significant injuries, but lots of sore muscles, scrapes, and bruises.
TiTou Gorge is a narrow chasm with a cold water stream in which you swim or float to where a hot water stream cascades over you and into the pool. It's a unique and relatively easy adventure.
The Trafalgar Falls hike takes you into the jungle, climbing and sliding over huge boulders into a beautiful valley where you can soak in hot water pools and view the picturesque falls. It's a workout, so you must be in decent shape.
The Carib Indian region on Dominica's eastern side is the only remaining home of the indigenous Kalinga people who originally populated the entire Caribbean. Here, those who want still live in the old-world ways. Schedule a tour through your hotel, and the people will be pleased to show you their old culture, homes, and handicrafts.