Let's start by crunching the numbers: the Rhine falls in Switzerland are 23 m tall and 150 m wide (boat for scale). On average, in summer, 600 cubic metres of water pass through every second. That's 600 000 Litres - assuming you need 2 L of water per day and will live to 80 years old, that's easily 10 times more water than you will drink in your entire lifetime, past your eyes in one second. Every second. Of every day. They don't turn this off at night!
Obviously, this is quite the unstoppable force, and the people at Rheinfall have figured out several ways to allow visitors to witness this force up close. A trail down from Schloss Laufen to the river side includes several platforms right next to the rushing water. It's noisy, it's impressive, and definitely humbling to be almost in the path of a wall of water.
But several steps further are available: boat rides that go against the current, right into the stream of the waterfall, and, not to be outdone, a boat that goes to the jagged rock smack in the middle of the falls, and drops you off for 20 minutes. I didn't do those because I was wet enough just from the rain, but it was tempting. So was a zip line in the hills, but man, if there was a zip line crossing the Rhine in view of the falls - not over them directly because that would spoil it for everyone else, but around where one of the boat crossings is -, that would be incredible!
Speaking of that rock in the middle, I love it. It's a masterpiece of erosion, and still taking the full force of the Rhine... for now. In a few thousand years I guess we won't be sending so many people there.