Seeing without digging

Since 2016, Dr Chloe Duckworth, a lecturer in archaeological materials science at Newcastle University, has been working at the ruins of Madinat al-Zahra, a medieval Arab city just a few kilometres from Cordoba in southern Spain.

In the 1920s the site was listed as a national monument, limiting the amount of archaeological work that can take place.

Now, in the first major attempt to understand the layout of the hidden medina (madinat) and history of how people lived in the Caliphal city, Dr Duckworth and her team have used new, non-invasive techniques to map the buried city using geophysics and an innovative portable X-ray.

Pinpointing where and how materials were produced – without having to move a single piece of earth - the team have found high concentrations of traces of lead and other metals in certain areas, giving clues to the types of industry that were taking place in the city. They have also identified the possible location of the kilns that were used to make pottery and ceramics due to changes in the soil’s magnetism revealing it had been heated to very high temperatures.

The discovery of the layout of the wider medina is one of the factors that prompted UNESCO to give the city World Heritage site listing. In confirming the new status, it highlighted Madinat al-Zahra’s "exceptional state of conservation both of its remains, and of adjacent areas".

Dr Duckworth explains: “Much of the medina and its urban layout has been preserved intact, making it a ‘time capsule city’. These new non-invasive survey techniques allow us to ‘see’ beneath the ground and give us real-time feedback about what’s going on without having to dig. This has given us a much greater understanding of the site as a whole – including the areas outside of the palace where ordinary people lived and worked.” 

’Time capsule city’

Madinat al-Zahra was built from scratch in the early 10th century by Abd al-Rahman III as a symbol of his power after declaring independence from the Emirate of Cordoba and pronouncing himself as Caliph. Following his death, the city was quickly abandoned barely 100 years after it had been established and lay undiscovered for almost a millennium until the first excavations took place in 1911.

Consisting of a palace and an accompanying city, the site was previously thought to be Roman ruins and referred to just as ‘Old Cordoba’.  Spread over 100 hectares – about the size of 120 football pitches - visitors are only able to see a third of the site, including the palace and main mosque, the rest of the city has remained buried.

The UNESCO recognition will give the site much greater prominence, as Dr Duckworth comments: “Because it was so short-lived, the city of Madinat al-Zahra has been largely forgotten so this announcement is really important for putting more attention on the site and giving greater prominence not just to the palace but to the city as a whole, safeguarding its place in the Islamic heritage of Andalucia.”

Working with colleagues from Bournemouth University, the next challenge will be to understand what different parts of the city were used for, and who lived and worked there. Work is planned to start early 2019 and the team say that the real-time data provided by the non-invasive techniques they use will give them much greater confidence to carry out targeted excavations, ensuring the continued preservation of the city.