Those monuments (from humans or from nature) should be obvious knowledge, but I generally don’t know any of them. It helps pacing the road trip, and be able to say “Mom, I’m at the level of the [Sainte Baume, for me]”.
They are shown on Michelin maps and atlas. We love to travel using the atlas and stopping on interesting sights or roads. Usually in France you can go from A to B the fast and boring way, or the slow and scenic way which is perfect for holiday time