The Rumichaca-Pasto road corridor, managed by Concesionaria Vial Unión del Sur (Sacyr Concesiones), is one of Sacyr's most relevant projects in Colombia. 

During the construction process, we discovered hundreds of archaeological remains that have been examined by Marcos Martinón-Torres.

Martinón-Torres, curator of the largest exhibition in Europe of the terracotta warriors of Xi'an (China), coordinated the analysis of these items with David Alejandro Pérez Fernández, Head of the Preventive archaeology program for Rumichaca-Pasto project between 2016 and 2023. Currently, he oversees archaeological tasks at the Unión vial Camino del Pacifico project, another Sacyr contract in Colombia. 

Martinón-Torres; Lina Campos Quintero (left), archaeologist at the Gold Museum; Kate Klesner, research associate with Martinon's team, and David Alejandro.

"The Nariño region has vast archaeological wealth. The discoveries made in the Vial Unión del Sur project are extraordinary and among the largest in Colombia's recent history. Excavations have unearthed pre-Hispanic tombs that provided us thousands of objects, revealing the richness and diversity of their technologies and funerary rituals," says Martinón-Torres.

 "Thanks to the excellent work of Sacyr's archaeologists, we have been able to carry out a very important part of our Reverseaction project, funded by the European Research Council. This project aims to explain how stateless societies mastered complex and luxurious technologies, such as goldsmithing, textile production, and precious stones. Items of this kind are usually associated with kings or pharaohs," explains the researcher.

"Including the perspective of European researchers and advanced scientific techniques is helps expand the possibilities of interpretation of the archaeological materials found during the archaeological excavations at the Rumichaca-Pasto widening project. Their insights help establish deep reflections about the ancient of this region, their way of life and how they connect to the technology at the time applied to ceramic arts", explains David Alejandro. 

"We carry out scientific analyses using various techniques from different scientific disciplines (natural, geological, and physical) to better understand objects that are 1,500 years old," explains Martinón-Torres. 

The three main techniques he uses are:

-    Chemical analysis on ceramic objects to understand the clays and pigments used.
-    Scanning electron microscopy to observe the items’ microstructure.
-    3D modeling to study their morphology and better understand their manufacturing processes.

"The collaboration with David Pérez and the Sacyr archaeologists has been incredibly enriching and synergistic. From the beginning, they have been open to sharing their discoveries," explains the archaeologist. 

"We were impressed by the professionalism of the archaeological record and the extent of excavations and items found. Upon our arrival, all the excavations were already completed. We have been able to add to our scientific contributions based on Sacyr's archaeological work," says Martinón-Torres.

"There is still much to do. As our project is currently planned, it will go on until 2026. We plan to return to Pasto at the beginning of next year to begin disseminating the results and take further steps. We will also develop our collaboration with the Gold Museum in Pasto, as well as with indigenous communities," this scientist says. 

The team has begun collaborating with native communities to better understand their history and integrate pre-Hispanic technologies into today's traditional crafts. "We can only do this work if we feel welcome and can contribute something to the local communities," he stresses. 

For example, Prof. Martinón-Torres’ team is collaborating with a community that is searching for clays for traditional pottery. Researchers compare these clays with those used thousands of years ago to better understand pigments used in the past. 

Kate Klesner, a postdoctoral research associate at the University of Cambridge and a member of Martinón-Torres' team, has worked with students from universities in Colombia to analyze these findings.

"The idea is to publish an article with Kate and Marcos; hopefully this year. The combined research reports amount to close to 4,000 pages, and they are an excellent groundwork for a book that will expand our knowledge about the human societies that inhabited this part of the world," says David Pérez.

According to Martinón-Torres, the excavations in this area are some of the most extensive and abundant known in the world.

ISABEL RUBIO ARROYO | Tungsteno

Did you know that the Casa Rosada is not symmetrical due to the demolition of one of its parts? Why does it have a room full of false doors? What is the reason for its pink colour? We investigate the secrets of Argentina's seat of government, which was almost fitted with a great dome and hides priceless archaeological remains inside.

An asymmetrical masterpiece

The Casa Rosada is located in the historic centre of the Autonomous City of Buenos Aires. Its history begins in 1873, when the Palacio de Correos y Telégrafos (Palace of Posts and Telegraphs) was erected. A few years later, President Julio Argentino Roca dreamed of a definitive government palace. He designed it next to the Palacio de Correos. In 1886, the two buildings were joined by the majestic portico that now greets the Plaza de Mayo. Thus was born the Casa Rosada. More than half a century later, in 1938, the south wing was demolished, as a result of which the Casa Rosada is no longer symmetrical.

A hall full of false doors

The White Hall is where the most important acts of government take place. It is where official ceremonies are held, foreign dignitaries are received and important decisions for Argentina are made, such as the signing of international treaties. The balcony or high gallery that surrounds it hides a secret: it is adorned with false doors covered with mirrors. The aim is to create a sense of greater breadth and depth, enhancing the grandeur of the space. “Only one of the doors opens, the one located in the centre of the right-hand sector leading into the hall,” says the official website of the Casa Rosada.

The White Hall is the main hall of the Casa Rosada. Credit: Casa Rosada official website.

The mystery of its colour

The choice of pink for this emblematic building is often attributed to President Domingo Faustino Sarmiento. It is said that Sarmiento, who assumed the presidency in 1868, used the mixture of white and red to symbolise the union of all the political sectors of the time. “According to some versions, the original method used to obtain the characteristic pink colour of the Casa de Gobierno was to mix lime with cow’s blood, a common technique at the time due to the water-repellent (to avoid moisture and filtrations) and fixing properties of the blood,” says the official website.

The dome that never was

The Casa Rosada was on the verge of having a majestic dome on its west façade. In 1907, the General Directorate of Architecture presented a project to transform the building's appearance. The idea was to construct a great dome that would symbolise grandeur and modernity. In the end, however, the project was never carried out. The reasons why it was left on the back burner of history are not documented.

The Casa Rosada was on the verge of having a majestic dome. Credit: Casa Rosada official website

The buried past of the Casa Rosada

At the beginning of the 20th century, excavations were carried out in the Patio de las Palmeras of the Casa Rosada and an unexpected discovery was made: rounded stones that, according to the renowned archaeologist Juan Bautista Ambrosetti, could be instruments used by the indigenous people of the area. Specifically, he suggested that they could be stones from boleadoras (a throwing weapon used mainly for hunting) or hatchets used by the Querandí people, indigenous South Americans who inhabited the Pampean region of present-day Argentina.

These are not the only mysteries hidden in the Casa Rosada. In fact, other surprising discoveries have been made under its floors. Most recently, in 2018, during the excavation of a pit for the installation of new lifts, ruins were found three metres underground. They belong to the Palace of the Viceroys of the Río de la Plata and date back to the 18th century. All these curiosities make the Casa Rosada more than just a government building. It is a unique place that attracts millions of tourists every year for its historical, cultural and architectural value.

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