View of the Rheinfall Switzerland.
From Wikipedia:
The Rhine Falls (Rheinfall in
German) are the largest plain waterfalls in Europe.
The falls are located on the High Rhine between the
municipalities of Neuhausen am Rheinfall and Laufen-Uhwiesen,
near the town of Schaffhausen in northern Switzerland, between
the cantons of Schaffhausen and Zürich.
The 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. Up to the end of the Wolstonian Stage approximately
132,000 years ago, the Rhine flowed westwards from Schaffhausen
past Klettgau. This earlier riverbed later filled up with
gravel.
About 132,000 years ago the course of the river changed
southwards at Schaffhausen and formed a new channel, which also
filled up with gravel. Part of the Rhine today includes this
ancient riverbed.
During the Würm glaciation, the Rhine was pushed far to the
south to its present course, over a hard Late Jurassic limestone
bed. As the river flowed over both the hard limestone and the
easily-eroded gravel from previous glaciations, the current
waterfall formed about 14,000 to 17,000 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.