The Rheinfall (Rhine Falls) were formed in the last ice age, approximately 14,000 to 17,000 years ago, by erosion- resistant rocks narrowing the riverbed. The first glacial advances created today's landforms approximately 500,000 years ago.
The Rheinfallfelsen, a large rock, is the remnant of the original limestone cliff flanking the former channel. The rock has eroded very little over the years because not too much sediment comes down the Rhine from Lake Constance.
<a href="//commons.wikimedia.org/wiki/User:AdMeskens" class="mw-redirect" title="User:AdMeskens">Ad Meskens</a>
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<span class="int-own-work" lang="en">Own work</span>