The Estrecho del Magdalena — the Narrows of the Magdalena — is where the great Río Magdalena, which runs the length of Colombia and drains much of the Andes, is squeezed through a gap between rock walls to a width of just 2 metres. The contrast is startling: one of South America's longest rivers, reduced to something you could jump across with a running start, rushing through a slot in the rock.
The site is about 7 kilometres from San Agustín and is easily combined with a visit to the main archaeological park — both are on the same side of the gorge. It is particularly impressive in the rainy season when the river is running high and the force of the water through the narrows is considerable. The surrounding area is green and photogenic, and the road there passes through typical Andean smallholder farming country.