In 1989 the photojournalist Andres Hurtado Garcia hiked across the remote rocky savannah below Colombia’s Sierra Macarena searching for an extraordinary river he had seen very briefly from the window of an aeroplane. The river he had seen was alive with vivid colours in a way that seemed to him impossible.
The area was at that time under FARC control and closed to travellers but Andres ventured in, found the river, took stunning photos, and broke the story in Colombia’s national press. The reaction was outstanding. The river became known as ‘the river of five colours’, ‘the river of rainbows’ and ‘the most beautiful river in the world’.
This is Caño Cristales, a 100km stretch of cascades, waterfalls, rapids, and bubbling shallow streams that tumble over a rocky bed carpeted in a very special plant that bursts into intense colours as each dry season arrives, transforming the shallow riverbed with its waving streams of purples, fuchsias, pinks, yellows and reds. It grows in large swathes, covering most of the river in kaleidoscopes of colour - a truly wonderful sight.
The landscape around it is wonderful too. The river flows through a rugged savannah that leads to the vertical walls of the table mountain of Sierra Macarena.
Caño Cristales is visually stunning and an inspiring place to visit. What has made it so very special?
Caño Cristales lies in the Sierra La Macarena national nature park, a region of mountains, savannahs and forests at the farthest extension of the Guiana Shield - one of the oldest rock formations on the planet dating back 1.8 billion years to Gondwana, the supercontinent that broke apart to form South America and Africa. The Shield’s extremely hard quartzite rock stretches from Guyana right across Venezuela into Colombia to the edge of the Andes (which has been pushed up by this tectonic plate meeting another). The Guaina Shield itself is noted for dramatic table mountains or tepuis, including many in Venezuela such as the ‘Lost World’ of Mount Roraima, and rolling savannahs called caatingas with extremely poor soils.
The table mountain of Sierra La Macarena is the last of the Guiana Shield’s great tepuis before the Andes. It runs north for 120km from the community of La Macarena, reaching altitudes of 2000m. Caño Cristales runs across the caatinga landscape below the tepuy, its waters flowing down to join one of the tributaries of the Orinoco, eventually reaching the Atlantic 2500km away.
Flowing over very hard rock across nutrient-poor caatinga means that the waters of Caño Cristales itself are extremely pure and therefore nearly sterile. There are no fish here, for example. It supports very few types of plant, but it is enough for the specially adapted Macarenia clavigera – an endemic species of riverweed – to survive and thrive here and in a small number of other rivers in the park. Because the water is so empty of nutrients, the high light levels and reduced waterflow mean that in the drier months the plant cannot make green chlorophyll to capture the energy it needs, but instead can only produce a less-demanding alternative (called phycoerythrin) which is bright red. The plant makes this switch gradually, in response to sunlight, temperature and available nutrients, changing through different hues as it does so and producing the brilliant kaleidoscopes of colour we see in bright sunlight. Variations each year’s rainfall and sunlight mean that a part of the river might be brilliant pink one year, the following year bright yellow, and glowing with rich purples the next.
That’s the science. The result is magnificence.
The community of La Macarena, the nearest small town, looks after this part of the park. Ecotourism brings welcome benefits to the town, and in return the community takes measures to safeguard the park, setting careful limits to the number of visitors and rules to protect the delicate ecology of the park and of Caño Cristales itself.
As well as butting up to the Andes here, the Orinoco’s Guiana Shield has become fragmented in this region into a mosaic interleaved with Amazon geologies. This convergence of Orinoco, Andes and Amazon ecozones within the national park and its mix of altitudes creates a special biodiversity hotspot. 500 bird species and 100 mammals have been recorded here.
Although Canño Cristales began to be recognised as a very special place in 1989, it then had to wait for real headway in the peace process before it became accessible. The river then became an emblem to the world of Colombia’s progress. In 2014, with talks with the FARC still ongoing in Havana, the President invited Prince Charles to join him to see the river during Charles’ tour of Mexico and Colombia – a much publicised event that would have been unthinkable a short time before.