The study examines eight soles dating back 2,000 to 2,400 years that were found at the Urium mining site and demonstrates the continuity of this type of footwear over several centuries in the mines of the southwestern Iberian Peninsula
A team from the University of Granada has studied eight esparto grass sandal soles, between 2,000 and 2,400 years old, found at the Urium mining site in Riotinto (Huelva), within the complex of ancient Roman mines in the area. The results of the research—published in the journal Pyrenae under the title “New Examples of Esparto Footwear in a Mining Context.” Excavations in the ‘Nuevo Filón Norte 1’ sector at Urium (Riotinto, Huelva)—reveal that this type of footwear was used continuously from the Iron Age through the Roman period, documenting a tradition of craftsmanship and functionality that endured for several centuries in the mining operations of the southwestern Iberian Peninsula.
The specimens were found in the Nuevo Filón Norte 1 sector of the former mining district, within two large accumulations of ash resulting from the cleaning of metallurgical furnaces. These conditions led to the exceptional preservation of the plant fibers—a rare occurrence for perishable materials—and have made it possible to study in detail archaeological artifacts for which there are virtually no other preserved examples.
In addition to the sandals, the excavations—carried out by the company Atalaya Riotinto—have yielded other objects made from plant fibers, including ropes and baskets, preserved thanks to the same exceptional conditions at the site. This collection provides new insights into the everyday use of perishable materials in Urium, a type of evidence that rarely survives to the present day. These findings provide new insights into daily life in the mining districts of ancient Hispania and into the material conditions of those who worked there. They also highlight the importance of the harvesting of plant fibers and their transformation into everyday products within ancient craftsmanship.
One of the most significant conclusions of the study comes from the carbon-14 dating performed on three of the sandals. The analyses show that the pieces date to different periods: one dates to the 1st century CE, another to between the 2nd and 1st centuries BCE, and the oldest to between the 4th and 2nd centuries BCE. This chronological diversity demonstrates that this type of footwear was present in the mining settlement for several centuries, from the Iron Age through the Roman period.
The sandals are made of braided esparto grass (Stipa tenacissima), a strong and flexible fiber that grows abundantly in the southwestern part of the Iberian Peninsula. The study has made it possible to reconstruct the manufacturing process and document the high level of technical expertise possessed by those who made them. In fact, analyses indicate that the sandals’ construction involved precise planning, in which the thickest and most uniform strands were used for the parts subjected to the greatest stress, while the thinner ones were used for lacing and fastenings. The researchers note that this combination of materials and uses reflects skilled craftsmanship and an advanced understanding of esparto’s properties.
To analyze the artifacts without damaging them, the research team used scanning electron microscopy and X-ray microtomography. This phase of the research, conducted at the Singular Laboratory of Archaeometry and the Center for Scientific Instrumentation at the University of Granada, made it possible to definitively identify the esparto grass and to precisely document the braiding techniques used. Furthermore, the research has also revealed significant wear on the soles, particularly in the forefoot and heel areas. Most of the sandals are missing the straps that secured them to the foot, suggesting that they were discarded only after they had reached the end of their useful life.
The collection studied also constitutes one of the largest groups of Roman-era plant-based footwear documented to date on the Iberian Peninsula. Its analysis expands the limited known record for this period and allows for a comparison of the Riotinto pieces with finds from other mining sites in Hispania.
Researchers associate this type of footwear with the solea spartae mentioned in Latin sources. These sandals would have provided protection and traction for workers in a particularly demanding environment; thus, their continued presence over centuries reflects their utility in mining operations.
The research is part of the TEXLUS project, funded by the State Research Agency and ERDF funds, dedicated to the study of the textile craft economy in Roman Lusitania.
Bibliographic reference:
BUSTAMANTE-ÁLVAREZ, M.; PAJUELO PANDO, A.; DORADO ALEJOS, A.; LOBO TORRES, M. A. New examples of esparto footwear in a mining context. Excavations in the “Nuevo Filón Norte 1” sector at Urium (Riotinto, Huelva). Pyrenae, 2026, vol. 57, no. 2, pp. 79–112. DOI: 10.1344/Pyrenae2026.vol57num2.4.
Link to the original publication:
Contact:
Macarena Bustamante-Álvarez – mbustamante@ugr.es