Seven Coloured Earths

The dunes occupy a surprisingly small footprint — you can walk the full circuit of the viewing boardwalk in twenty minutes — yet the effect of the striped bands of red, ochre, violet, green, blue, purple and yellow sand is entirely unlike any natural formation you are likely to have seen, the colours so saturated and evenly distributed across the hillside that they appear printed rather than weathered, and visitors consistently report that photographs of the site look more manipulated than the reality.

The formation results from the decomposition of volcanic basalt into clay, which further transforms into ferralitic soil through a process of total hydrolysis; the iron compounds produce the red and brown tones while aluminium compounds generate the blue and purple hues, and the mechanism by which the differently coloured mineral particles settle into persistent horizontal bands rather than mixing into a homogeneous mass — despite constant rainfall, wind and gravity — is still not fully understood by geologists and remains an active research question.

A wooden boardwalk rings the dune area, preventing visitors from disturbing the surface, and viewing platforms at intervals allow you to see the bands without obstruction — the low morning light catches the relief of the ridges between bands and intensifies the colour contrast in a way that the harsh midday sun flattens, and after rain the individual bands become even more distinct as the moisture brings out the full saturation of each colour layer.

Adjacent to the coloured earths, the Chamarel Falls descend in a single broad curtain over the cliff face of the Rempart mountain, the water landing in a misty pool below that is itself surrounded by forest; the falls are visible from the same ticket as the coloured earths and can be reached by a short path through the plantation that surrounds the site, making the two attractions complementary and allowing visitors to see the water cascade from multiple angles on the walk down.

The surrounding area is part of a former Franco-Mauritian coffee plantation, and the land use shift from coffee to tropical hardwoods and spice cultivation has left the hillsides around the dunes still partially cleared, so that the geological formation appears even more isolated and alien against the green backdrop — a patch of bare coloured earth that looks entirely out of place in the lush tropical landscape.

Rain dramatically intensifies the colour saturation, and during the dry season the reds deepen to near rust while the greens fade toward yellow; the boardwalk signage explains the geological process in both English and French and honestly acknowledges the ongoing scientific uncertainty about the self-layering mechanism, a refreshingly candid approach to interpretive signage that adds to rather than diminishes the sense of wonder.

The site has been one of Mauritius's primary tourist attractions since the 1960s, and the curio shops at the entrance sell small sealed test-tubes containing samples of the coloured sand — a practice that is officially discouraged as ecologically unsustainable — but which reflects the irresistible quality of material that appears to have been artificially coloured rather than naturally formed, and visitors consistently take home these samples as the most tangible memory of a landscape that defies easy description.

The self-layering phenomenon — sands of different colours settling into persistent bands without human intervention — is geologically unique and has no accepted complete scientific explanation.

The visual effect is extraordinary and unlike anything in the volcanic island chain of the Indian Ocean.

Combined with the nearby Chamarel Falls and the Ebony Forest, the Chamarel plain offers the most concentrated natural sightseeing circuit in south-western Mauritius.