The city of Venice is made up of 117 islands that are linked together by water canals, numerous small bridges, as well as 3 large bridges of the Grand Canal. In the lagoon of Venice, there is a collection of a small island of rock and mud where people started driving wood pilings into the mud and sand and into the clay. The wood was gathered in a forest far away in the mountains of Slovenia, Croatia, and Montenegro and then transported by water to Venice.
The wood does not rot as it is not exposed to oxygen when it is submerged in the water and mud. The wood becomes hardened like a stone-like structure due to the crystallization of mineral in the mineral-rich water passing through it.