The dunes contain marine fossils dating back to the Quaternary period, providing records of ancient climate changes.
The field is technically a 'transverse' dune system maintained by constant southerly wind patterns.
The site was officially declared a Nature Sanctuary in 1993 to mitigate urban encroachment.
The dunes act as a natural barrier that regulates the microclimate of the surrounding coastal slope.
Researchers have identified several endemic plant species that have adapted to the high-salinity, sandy soil conditions.
The Concón Dunes, known locally as Dunas de Concón, are a coastal dune field covering approximately 25 hectares on the border between Concón and Viña del Mar. These formations are classified as a Nature Sanctuary (Santuario de la Naturaleza) due to their unique geological status and fossil-rich layers. The dunes serve as an active site for sandboarding and recreational hiking. They are situated on elevated coastal cliffs, providing panoramic views of the Pacific Ocean and the mouth of the Aconcagua River. Development in the surrounding area has been a subject of ongoing environmental and legal debate, leading to restricted access zones to preserve the fragile ecosystem. The topography consists of shifting sands influenced by strong coastal winds. This site represents one of the few remaining coastal dune ecosystems in central Chile.
The summit of the highest ridge facing west, providing a clear vantage point of the coastline and the Aconcagua river estuary.
Wear athletic shoes with deep tread to manage the steep, shifting incline.
Bring wind-resistant eyewear, as the coastal breeze often kicks up fine sand.
Carry out all trash, as the ecosystem lacks formal waste collection services.
Do not attempt to climb the steepest faces if you are not physically conditioned for high-intensity sand resistance; avoid walking off-trail in marked conservation areas.
Stay on designated paths where marked to avoid damaging fragile, protected flora; pack out all personal waste.
