The Bastione is the grey Venetian watchtower on the slope above Riva. It was built in the early 1500s to guard the town from the north; now it is mostly a reason to climb, or take the panoramic lift, for a clean view over the rooftops, harbour, and blue wedge of Lake Garda.
Go early or late if you can. In the middle of a summer day the lift and terrace can feel crowded, but the view is still the quickest way to understand Riva's geography.