Most people imagine a river to be either dark and murky, or to be crystal clear with a few dull gray stones lining a somewhat unremarkable riverbed. Colombia’s Caño Cristales is the world’s most colorful river from late July to November. Red blooming plants proliferate in the river’s waters during the brief period between the wet and dry seasons. In addition to the gorgeous scarlet red that predominates in the river, there are splashes of yellow, green, black, and blue caused by mineral deposits, rocks, and different plants.

For most of the year, Caño Cristales is a pale green river that is not so different from most others rivers. The water level must be just right for Caño Cristales to transform into an aquatic rainbow. If the water level is too low, the crimson colored plants cannot grow. The red plants shrivel up and turn brown. Accessing Cano Cristales requires some serious planning, since it is located in a remote region of Colombia. Political upheaval kept tourists away from Cano Cristales for several years, but now the area has stabilized and the Colombian people welcome tourists with open arms.

Journeying from the town of La Macarena on horseback is a popular way to travel to Caño Cristales. Swimming is highly restricted, in the interest of keeping the fragile ecosystem intact. If you’re lucky, you may spot a giant’s kettle. A giant’s kettle is a circular hole that forms in the riverbed when flowing water jostles rocks and creates friction. It appears as a natural witch’s cauldron, with water wildly churning back and forth. Several giant’s kettles add to the mystique of a colorful river that looks as though it was imported from a distant planet.