Sometimes a simple hike along a river near a city (not in a wild region) can reserve some surprises.

Rocks can be arranged in vertical beddings that show particular shapes in the riverbed.

Beddings that generally would be horizontally arranged can be vertical, inclined, and also folded.

Waters can erode some finer beds living the harder ones to become a sort of natural menhirs...

or lithic fences.

This is nature and the nature has decided to erase all. T

he pictures were taken some ten years ago before a flood (and a hydraulic defense collapse) washed all the things changing the landscape of the river. 

The amazing rock outcrops shown in these pictures doesn't exist yet.