In 1545, Pope Paul III ordered that a new canal be built (the Pauline Trench). The plan was to expand the Curian Trench and to build a regulating valve to control the flow. Upon its completion some 50 years later (in 1598), Pope Clement VIII inaugurated the new work, and named it after himself: the Clementine Trench.
The Cascata delle Marmore or Marmore Falls is a man-made waterfall created by the ancient Romans. Its total height is 165 m, making it the tallest man-made waterfall in the world. Of its 3 sections, the top one is the tallest, at 83 m