A feat of geological engineering
The landscape of Cinque Terre is a massive work of civil engineering, constructed over a millennium. Roughly 7,000 kilometers of dry stone walls, known locally as muretti, form the terraces that make agriculture possible on the steep coastal cliffs. These walls support an estimated 8,400,000 cubic meters of earth, all moved by hand to create narrow, farmable strips of land called ciàn. Construction, which began around the 11th century, involved breaking up the native sandstone and marl bedrock and meticulously stacking the stones without any mortar.
This ancient technique has a deep scientific function. The walls are permeable, allowing rainwater to drain through them. This prevents the soil from becoming saturated, which would otherwise lead to catastrophic landslides on the young and steep slopes of the Ligurian Apennines. The local geology is dominated by Cretaceous and Oligocene flysch deposits—layers of sandstone, claystone and limestone that are prone to erosion. The terraces transform the near-vertical cliffs into a managed hydrological system, drastically reducing the risk of slope failure. The entire structure is evidence of a deep, practical understanding of soil mechanics and hydrology.
The ecology of abandonment
The stability of this man-made ecosystem depends entirely on continuous human maintenance. When agricultural activity ceases and the muretti are no longer repaired, the system begins to fail. Unmaintained walls collapse under pressure from soil and water, triggering a rapid increase in erosion. Studies in similar terraced environments show that erosion rates on abandoned terraces can be more than ten times higher than on well-maintained ones or natural hillslopes. The 2011 floods in the region showed this vulnerability, with the most severe landslides originating from abandoned, unmaintained terraces.
This degradation has cascading ecological effects. Topsoil painstakingly accumulated over centuries washes into the Ligurian Sea, impacting marine life. The land itself, once productive, is lost. Historically, these terraces supported a robust agricultural economy, primarily centered on viticulture. The main grape varieties grown are Bosco, Albarola, and Vermentino, which are used to produce the region's DOC white wines and the famed sweet wine, Sciacchetrà. This form of cultivation is often called "heroic viticulture" due to the extreme difficulty and manual labor required, with no possibility of mechanization on the steep, narrow plots. Today, only a fraction of the original 2,000 hectares of terraced farmland remains actively cultivated, posing a serious threat to the future of this unique landscape.