From the World Heritage inscription:
Morne Trois Pitons is located 13 km east of the town of Roseau in the highlands of south-central Dominica and it is the basaltic spike-like remains of a former volcano rising to approximately 1,300 m, within 8 km of the sea.
The landscape is characterized by volcanic piles with precipitous slopes, and deeply incised valleys (glacis slopes). There is also a fumarole known as Valley of Desolation (or Grand Soufriere), with fumaroles, hot springs, mud pots, sulphur vents and the Boiling Lake, which is the world’s second largest of its kind. The valley is a large amphitheatre surrounded by mountains and consisting of at least three separate craters where steam vents, small ponds, and hot springs bubble up through the ground. Boiling Lake is surrounded by cliffs and is almost always covered by clouds of steam. The Valley of Desolation drains into the Pointe Mulatre River, which flows into the Atlantic.
Other outstanding features in the area include the Emerald Pool, fed by the Middleham Falls; Stinking Hole, a lava tube in the middle of the forest; and the Boeri and Freshwater lakes. The Freshwater Lake is the largest and second deepest of Dominica’s four freshwater lakes. The Boeri Lake is the second largest in Dominica, and is located in the crater of an extinct volcano. Both lakes are separated from each other by Morne Macaque (1,221 m) and vary in depth with the season. Both are thought to have originated some 25,000-30,000 years ago. The park also encompasses almost all the headwaters of the streams and rivers in the southern half of the island.
Morne Trois Pitons National Park is the jewel of an island which itself might be the jewel of the Caribbean.
Dominica is a wild island that is still volcanically active. There are few beaches on the island, but the lack of beaches are made up for by 365 rivers, many mountains, the world second largest boiling lake and stunning lush scenery. Many parts of the part are only accessible by hiking. Some spots, like the boiling lake, require a full days hike to get there and back.
The waterfall in the photo is Upper Trafalgar falls which is right next to Lower Trafalgar falls. Despite being right next to each other, the falls from rivers with completely different sources.
Dominica is the least visited country in the Western Hemisphere because the airport cannot handle large airplanes, but that shouldn’t deter you from visiting. It is unlike any other island in the Caribbean.