In a remarkable feat of engineering that defies conventional construction, a suspension bridge made entirely of grass stands strong against storms, rain, and constant foot traffic. This astonishing reality comes from the Inca civilization of South America, whose descendants continue to build these grass bridges, captivating the world.

These bridges begin to weaken roughly a year after their construction. At that point, the Inca people embark on a new cycle of bridge-building using their innovative methods.

This ancient warrior civilization’s unique technique is truly astounding. Their journey involves crossing treacherous rivers in extremely difficult terrain using extraordinary technology. The Apurímac River flows past the Cusco region of Peru, and it is in its basin that the successors of the Inca civilization reside. The bridges they use to cross the river are made of grass.

For centuries, new grass bridges have been built in the same location. Each time, the old bridge is cut and its grass is released into the river—a custom the Inca people believe honors nature, returning what nature has given. One such extraordinary grass bridge is located in Q’eswachaka.

This bridge is constructed from a special type of strong grass called Q’oya Ichu. How is it built? Each rope of the bridge is woven by hand. Before weaving, each blade of grass is pounded flat with stones and then soaked in water for an extended period to ensure flexibility. The Q’oya Ichu grass bridge has stood in this challenging area for 600 years, with its grass replaced annually even though the location remains the same. In 2013, this bridge was recognized as a UNESCO World Heritage site.

These bridges served as vital connections between important regions of the Inca Empire, enabling passage over swift-flowing rivers despite the inherent risks. According to Inca tradition, only adult men are permitted to participate in the construction of these bridges, while women sit on the mountainside and weave smaller ropes.

Before installing a new bridge, the men remove the old one. They bundle the smaller ropes together. The main foundation of the bridge consists of six large braided ropes, each about one foot thick, made by twisting together 120 thinner ropes. This entire bridge-building process uses no modern equipment or machinery, relying solely on grass and human effort.

During construction, the Inca divide tasks among themselves. Those involved in cooking do not work with the grass. Cooks prepare meals over wooden stoves, which are collected from various parts of the village. They prepare a variety of foods, including chicken, guinea pig, and trout. However, every meal must include locally grown potatoes of various shapes and colors.

The most daring individuals risk carrying the grass ropes from the top of one mountain to the top of another. These main ropes then form the basis of the bridge. The grass remains perfectly intact through storms, water, or any natural disaster, but it must be discarded after one year. The Inca believe that nature’s gift has a lifespan of only one year.

After the Q’eswachaka bridge is completed, a feast and musical performances are held. The bridge-building ceremony typically lasts four days. The festival takes place on the fourth day, which falls on June 2nd each year.