The Roman Wall of Lugo was declared a World Heritage Site in the year 2000 for being the best-preserved example of late Roman military fortifications in Europe. The modifications it has undergone over its more than 17 centuries of existence have not substantially altered its original appearance and layout, which follows the guidelines of the Roman engineer Vitruvius. It is the only one in the entire territory of the Roman Empire that retains its entire perimeter, and its presence has determined the history and urban evolution of the city of Lugo, increasing and enriching its cultural interest.
The Wall surrounds the heart of Lugo, the ancient Lucus Augusti, founded in 15 B.C. by Paulo Fabio Máximo in the name of the Roman emperor and was the capital of one of the three Roman juridical convents (along with Astorga and Braga), which formed the province of Gallaecia and extended to the Douro River. This city played a crucial role in a region that was then extremely rich in gold, which Rome exploited to exhaustion for the benefit of the imperial treasury. Three centuries later, the urban structure of the city changed and shifted slightly to the north. These were critical times from a political and military standpoint, and it was at this moment that this fortification was erected. The wall occupied an area of topographically irregular terrain, higher in the northwest and descending towards the southeast. The reasons for this layout, which left important residential areas of the ancient Roman city outside and instead protected open lands, remain a mystery. Despite the reforms it has undergone, the Wall retains its original layout and the construction characteristics that give it a massive and sturdy appearance, typical of its defensive nature.
Its rectangular shape with rounded corners exceeds two kilometers in perimeter, 2,117 m., and protects an interior area of 34.4 ha. Seventy-one of the original eighty-five exterior towers are preserved. The height of its walls ranges between 8 and 10 m. and maintains an average thickness of 4.20 m., reaching 7 m. at some points. Today, the interior of the Wall is accessed through ten gates that cross it, 5 ancient and 5 of modern design and opening; from the inside, you can access its walkway through four exterior staircases and two inclined ramps, one of which continues into an interior ramp. An exterior moat about 20 meters wide and at least 5 meters deep is known to have existed, which would complete the defense, making it difficult for siege machines to approach or for mines to be dug. Having lost its military function, the Roman Wall of Lugo has become fully integrated into the current urban structure: it surrounds the historic city, and its walkway is a promenade, or another pedestrian street, regularly used by its inhabitants and visitors. On the walkway, coinciding with the original towers, double-flight interior staircases of imperial design are preserved, connecting it with the inner wall, where they do not reach the ground; various hypotheses interpret this as a defensive resource that allowed the enclosure to be isolated by removing the mobile staircases or ramps that provided access to the first step. Currently, 22 of these staircases have been discovered and archaeologically investigated.