Beams rise above the forest canopy. The illuminated scaffolding stands out against a backdrop of a thousand shades of green.

And so, little by little, the Riosucio viaduct is taking shape. At 660 meters long with spans of 120 meters and a height of up to 45 meters over the water, this bridge is one of the central pieces of the Ruta del Cacao, a new corridor from Bucaramanga to Barrancabermeja connecting the regions of Santander and Antioquia with the Magdalena River, Colombia’s major river highway.

The project consists of remodeling and renovating the roadbed, as well as creating a corridor approximately 152.95 km in length with two lanes in each direction between Bucaramanga and Barrancabermeja.

The Riosucio viaduct is the longest bridge along the entire route. It is a mass of 160,000 kilos of steel and 7,900 cubic meters of concrete. Not far from both ends of the bridge, the Ruta del Cacao soon dives from on high to dive underground. The viaduct connects the La Paz (3.2 kilometers) and La Sorda (2.2 kilometers) tunnels, forming a three-way link that maximizes the infrastructure’s utility.

Still, along its 152 kilometers, the Ruta del Cacao is more than a way over the “Dirty River” and two holes in the ground. When work on this structure is complete, the two-lane highway will cross 33 other bridges and viaducts and connect two major locations in eastern Colombia. Until now, they’ve just been linked by a winding mountain road. It will then link Santander with the northeastern part of the country and with the route to Venezuela.

The mouth of the La Paz tunnel meets the Santander forest. This greenery rivals the pillars of the Riosucio viaduct in capturing the eye of the beholder. Beyond that are more mountains whose slopes get warmer as they reach Barrancabermeja and the thick air of the Magdalena River – or, as it is known in Colombia, the Rio Grande, the most important waterway in the country. It is navigable for hundreds of kilometers, making it a central part of commerce and of legends since time immemorial.