The black canyon of Sicily: the Alcantara River, chilly even in August, flows between basalt walls resembling organ pipes that rise up to 25 meters, sculpted by the meeting of lava and water. You can descend to the small beach via stairs (or the park's elevator), walk in the river with rented boots, or go body rafting in the wilder sections. The water cuts at your legs: it's part of the experience.
In the app, check in on site: you earn a point and the AI guide tells you about the place in your language.