The Hidden Labyrinth Beneath the Inca Capital

For centuries, tales of secret tunnels beneath the ancient Inca capital of Cusco were considered little more than legends. Today, archaeology is beginning to substantiate these claims in the ruins along the Pacific coast and Andean highlands of South America. Researchers studying the so-called chincana—a network of underground labyrinths—believe they have identified part of a system that once connected Sacsayhuamán, a large fortress overlooking Cusco, with Coricancha, the sun temple that served as the religious heart of the Inca Empire.

The project, led by archaeologists Jorge Calero Flores and Mildred Fernández Palomino, combines excavations, geophysical studies and the analysis of colonial records to trace these hidden passages, which extend for nearly 1.2 miles. The evidence ranges from historical documents to structures detected underground and material remains found during excavations, explains Calero Flores. These include walls, superimposed chambers and sections of corridors built with finely carved stone blocks.

“We have ethnographic and historical data as well as geophysical evidence of the existence of five underground passages connecting Sacsayhuamán with Coricancha, two of the most important sacred sites of the time,” says Calero Flores. “Coricancha housed the principal idol, Punchao [representing the Inca sun god]; Sacsayhuamán was known as the place where time was measured,” he notes. The identified passages are roughly between 3.3 and 8.5 feet wide and around 8.8 feet high, suggesting they may have been used by members of the Inca nobility traveling in litters, raised platforms used to carry nobles on the shoulders of attendants.

In addition to their possible practical function, the tunnel system may also have held symbolic significance within the Inca worldview. According to Calero Flores, the chincanas represented the womb of Pachamama, the Andean deity associated with fertility and the earth. They may have served as ritual spaces where the Inca—considered the son of the Sun—made ceremonial journeys with the Punchao—a pure gold effigy about 31 inches tall. "[Punchao] traveled through its depths, fertilizing the world like a celestial bridegroom,” he theorizes.

Several accounts from the 16th to the 18th centuries mention these hidden passages. In one text, the Spanish religious figure Martín de Murúa described a temple in the fortress of Cusco whose entrance was shaped like a serpent with its mouth open. From there, he wrote one could descend underground to the Temple of the Sun (where the Church of Santo Domingo stands today) through a labyrinth of caves and corridors where it was easy to get lost.

Centuries later, archaeologists believe they have identified the location referenced in that description. In the section of Sacsayhuamán that the team calls the “H-shaped temple,” Calero Flores and his colleagues claim to have recognized the form of that supposed “serpent’s head.” The area shows alignments linked to astronomical phenomena. According to their interpretation, the mouth of the figure is oriented toward the sunrise on August 1, the date of the traditional offering to Pachamama and the moment when the Pleiades constellation (known as Colca in Andean tradition), appears in the sky.

Excavations in that area also revealed evidence of later intervention. The team found remains of walls that appear to have been built to seal access to an underground passage. This hypothesis is further supported by historical documents stating that the 19th-century prefect of Cusco, Peru, Miguel de San Román, ordered some corridors to be walled up after several accidents occurred in the chincana between 1838 and 1842.

Alongside these walls, fragments of enameled tableware, wine jugs, crosses and traces of military occupation were discovered. Researchers believe these may be remains left by a regiment stationed at the site for a short period, possibly while the passageways were being sealed. All of this suggests that, rather than merely a legend, the chincana tunnels may have been known and even used in later periods.

In some areas, archaeologists identified possible chambers and corridors several feet deep. Geophysical studies using ground-penetrating radar and electrical resistivity tomography even suggest the presence of cavities about 50 feet underground.

In addition to the main tunnel, the team detected other smaller branches. One of these extends toward an area known as Muyocmarca, one of the towers at the highest point of Sacsayhuamán, where a passage carved into the bedrock and covered with finely crafted stone blocks was identified. This section appears to match a description given by Inca Garcilaso de la Vega in 1600. Another wing may reach the archaeological site of Callispuquio, while a third would pass behind the present-day Church of San Cristóbal.

The team hopes to find materials such as textiles, wood or even quipus—the system of cords and knots used by the Inca to record information—which could help shed light on daily life and ritual practices in pre-Hispanic Cusco.

Confirming the extent of this underground network, however, is not easy. According to Calero Flores, the possible passageways lie roughly 13 to 30 feet underground, depths that make them difficult to detect.

“The study of the chincanas of Cusco clearly shows that the Incas had an advanced knowledge of geophysics and structural calculations for building underground,” says Calero Flores.