| Name: | Aqueduct of Segovia |
| Commissioned by: | unknown |
| Construction period: | probably 2nd century AD |
| In operation until: | 1973 |
| Maximum height: | 28 metres |
| Number of arches: | 167 |
| Length of the visible structure: | 959 metres |
| UNESCO World Heritage Site: | since 1985 |
Aqueduct of Segovia: A Masterpiece of Roman Engineering
Location: The Aqueduct of Segovia runs from the Sierra de Guadarrama, a mountain range northwest of Madrid, to the historic centre of Segovia. Large sections of the ancient water conduit lie underground. Its best-known section crosses the city centre and spans the Plaza del Azoguejo. From there, the conduit continues underground to the Alcázar, the city’s medieval castle and palace complex.
Significance: The Aqueduct of Segovia is the symbol of Segovia and one of the most important surviving achievements of Roman engineering. Its highly visible arches continue to define the cityscape and provide a striking demonstration of the exceptional technical skills of Roman builders. The structure also appears on Segovia’s coat of arms and flag.
Construction History: The precise date when the Aqueduct of Segovia was built has yet to be conclusively established. Archaeological finds from the foundation pits suggest that the monumental arched section was constructed no earlier than AD 112, probably during the final years of Emperor Trajan’s reign or at the beginning of Emperor Hadrian’s rule. During the Middle Ages, the eastern section in particular suffered severe damage. The frequently repeated claim that troops belonging to the Muslim ruler al-Mamun deliberately destroyed 36 arches in 1071 is not supported by historical evidence. More likely causes include centuries of deterioration, leaking water channels, unauthorised water extraction and frost damage. Between 1483 and 1489, the Catholic Monarchs ordered the reconstruction of 36 damaged or collapsed arches and the repair of further sections of the water conduit. The Aqueduct of Segovia continued to be regularly maintained over the following centuries and remained part of the city’s water supply until 1973.
How It Worked: The water came from the Río Frío in the Acebeda Valley and flowed to Segovia along a carefully calculated gradient. Settling basins slowed the flow, allowing sand, soil and small stones to sink to the bottom. The monumental arched structure kept the water channel at the required height and carried it across a deep depression in the terrain to the historic centre. From there, the water travelled through a branching network of conduits to public fountains, cisterns and other distribution points. Using this system, the Aqueduct of Segovia could carry a maximum of approximately 20 to 30 litres of water per second into the city.
Architecture: The entire conduit system is approximately 16.2 kilometres long. Its above-ground arched sections have a combined length of around 959 metres and contain a total of 167 arches. The monumental section consists of approximately 20,400 granite blocks stacked without the use of binding mortar. At the Plaza del Azoguejo, two tiers of arches rise one above the other, reaching a height of around 28 metres at their highest point. The water channel ran along the uppermost level, while the massive pillars and rounded arches bridged the differences in elevation across the city. Much of the granite used in the construction came from the El Berrocal quarrying area near Ortigosa del Monte. Quarrying marks, working areas, forges and a Roman transport road provide evidence of a carefully organised stone-production process based on a clear division of labour.
Construction Method: Holes, notches and grooves dating from the Roman construction period can still be seen on many of the granite blocks. Metal lifting tongs were inserted into paired recesses and tightened around the blocks under their own weight as they were raised. Wooden lifting machines equipped with hemp ropes, pulley systems and large treadwheels hoisted the blocks to the upper sections of the structure, where they were precisely positioned using iron levers. Tall scaffolding also supported wooden centring frames on which the arch stones rested until the wedge-shaped keystone was inserted and the arch became self-supporting. Working on scaffolding at heights of almost 30 metres involved considerable danger.
Restorations: The Aqueduct of Segovia as it appears today does not consist entirely of original Roman masonry, but also incorporates repairs and additions made over several centuries. The first 49 arches in particular contain a mixture of different construction phases spanning a period of approximately 400 years. Some of the arches rebuilt at a later date can be identified by their slightly pointed shape and the different way in which the granite stones were worked.
The Lost Inscription: Above the Plaza del Azoguejo, the Aqueduct of Segovia was once decorated with a monumental inscription, probably formed from gilded bronze letters. The valuable metal letters were later removed and probably melted down, leaving behind hundreds of fixing holes and isolated traces of lead in the granite. Using these marks, ancient historian Géza Alföldy reconstructed a text indicating that two senior officials in Segovia had the water supply restored under Emperor Trajan. His interpretation is regarded as important and plausible, although it cannot be considered conclusively proven because the surviving marks are difficult to decipher and more recent archaeological findings have raised further questions.
The Madonna and Saint Sebastian: In 1520, the two central niches of the Aqueduct of Segovia were fitted with new Christian figures. Antonio de la Jardina, who tested the precious-metal content of coins at the Segovia Mint, donated the stone Madonna now commonly known as the “Virgen del Acueducto”. A wooden figure of Saint Sebastian stood in the opposite niche, but its poor state of preservation meant that it had to be removed in 1972. The Madonna statue, which weighs around one tonne, was removed and restored in 2019, while a considerably lighter replica now stands in its original location.
Traffic-Free Arches: Until 1992, a busy road passed directly beneath the Aqueduct of Segovia and was used by more than 20,000 vehicles each day. To protect the already weathered granite from exhaust fumes, dirt and further deterioration, the city permanently closed the route to traffic. This transformed the Plaza del Azoguejo into a largely traffic-free square where visitors can now experience the monumental structure at close range.
Famous Legend: According to an old legend from Segovia, the devil built the Aqueduct of Segovia in a single night. In the best-known version of the story, an exhausted water carrier promised him her soul if he could bring water to her house before the rooster crowed for the first time. When the young woman regretted her fateful pact, she prayed throughout the night to be saved. The rooster finally crowed before the devil could place the final stone, causing him to lose his claim to her soul. Since 2019, the “Diablillo de Segovia” on Calle San Juan has commemorated the legend in a humorous way. The sculpture depicts the defeated devil holding the final stone he failed to place while taking a selfie in front of his almost completed work.
Name: The name Segovia is of pre-Roman origin and is often associated with the Celtic word sego, meaning “strength” or “victory”. However, its exact origin and meaning have not been conclusively established, and the name could roughly be interpreted as “strong city” or “place of victory”. The word aqueduct comes from the Latin expression aquae ductus and literally means “water conduit” or “conveyance of water”.
UNESCO World Heritage Site: The Aqueduct of Segovia and the historic centre of Segovia have jointly been listed as a UNESCO World Heritage Site since 1985. The designation recognises the exceptionally well-preserved condition of the Roman structure and its outstanding importance to the historic cityscape.
