The mushroom monolith of Piana Crixia
Near the country ward Borgo, on the bank of a meander of the Bormida di Spigno, you can see the famous mushroom shaped monolith of Piana Crixia, a unique form of erosion for Liguria and the surrounding areas. Similar forms can be found in some alpine areas, where erosion shaped ancient morainic or fluvial-glacial deposits creating picturesque earth pyramids. The fifteen-meter high "Mushroom" is formed by a giant boulder of ophiolitic rock supported by a conglomerate column (sedimentary rock made by pebbles of different dimensions joined by thinner material). The boulder protected the underlying conglomerate column by washing out, while the surrounding ground was progressively swept away by erosion. It seems impossible that the high column of cemented pebbles can bear the weight of the giant stone above it, but we must consider that conglomerate is a solid rock, despite its detritus aspect. However, the ongoing process of erosion slowly takes away material, and in the future the stone is bound to collapse and the conglomerate column which will be no longer protected will be gradually swept away by the washing out of the rain.Piana Crixia, Highway A6 Savona-Turin, Altare-Carcare or Millesimo exits. State road towards Aqui Terme over passing Cairo Montenotte.From Piana Crixia on the way to Savona you can visit the Glass Museum of Altare and the Ceramic Museum of Albenga.
Ospitality in this area:
Stages of other paths