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From the panoramic viewing point in Tiglieto you have an excellent view of the overall morphologic context where the Tiglieto Abbey was built. At the same time, natural fluvial forms and hydraulic engineering works carried out over the years can also be seen. On the underlying level ground you can imagine the original flow of the Torrente Orba which ran along a narrow creek which in geological terms is called a “meander”. You can clearly see the (manmade) river opening where the Torrente Orba now flows. You can see another “entrenched meander” form in the rock by continuing another 50 metres by foot along the road towards Olbicella, looking to the right of the rail.
Looking at the outer side of the meander under your feet you can see that the bank of the Orba is made of naked rock, while on the opposite side (the inner lobe) you can see little pebble and sand beaches. During the rainy reason, the river in flood flows towards the river mouth very energetically. By following the meander, the strongest current is pushed to the exterior by centrifugal force, a bit like with a car when it turns a hairpin bend. Following swiftly at the outer part, the water erodes the bank, creating a scarp of erosion with the rock of the substratum in view. In the inner part of the meander (the lobe) where the river has less energy, instead of eroding the bank there is a tendency to deposit pebbles and sand from the mountain, forming little beaches. The meanders are called “entrenched” when they flow in flat areas, running through narrow mountain valleys, like for example the Grand Canyon in the United States of America. In this case, as with the Piana di Tiglieto (though notably smaller in size), a torrent flowing in meanders probably on flat ground carved the ridges after a tectonic upthrust of the substratum, maintaining such meander ripples in the rock.
