# 3D Documentation with TLS of Caliphal Gate (Centa, Spain)
## 3 Results  
### Ceuta and the Caliphal Gate  
Ceuta (Figure 2) is a Spanish autonomous city on the Northern Coast of Africa, neighboring with Morocco. It is 14 miles away from Cadiz and, according to the Spanish National Institute of Statistics, its population was 84,913 inhabitants in January, 2018 [42]. Its extension is 18.5 km\({}^{2}\). The first evidences of human occupation in the area have an age of about 270,000 years, although the current urban core has been inhabited for 2700 years [43]. Given its strategic position on the southern side of the Strait of Gibraltar, it is possible to trace several historical periods of colonization or domain: Phoenicians, Mauritanians, Romans, Byzantines, Muslims, Portugal, the Iberian Union, and finally, Spain.  
The necessities of defense related to its location implied the construction of walls around the city. The Caliphal Gate (Figure 3) is a reminiscence of the medieval defensive wall that was hidden by the subsequent works that configured the royal walls of Ceuta (Figure 2b), which were declared an asset of cultural interest as historical ensemble in 1985.  
Figure 2: (**a**) Location of Ceuta. (**b**) General sight of the city and the royal walls.  
It is thought that Romans built the first closures, but no remains of walls have been found to confirm it. The construction of the medieval wall that surrounded the Islamic media (with the main religious and politic buildings, wealthy residences, and other facilities, such as baths) was started by [PERSON] and finished by his son, [PERSON], in 962 [44]. Although the basic layout of this defensive structure was maintained until 1541, it suffered severe damages through the Portuguese siege (1415). Those circumstances made it necessary to accomplish great works to guarantee the security of the site.  
On June 28 2002, the Caliphal Gate and part of the medieval barrier were discovered during a visit inside the part of the royal walls that communicates with the National Tourism Paradox \"La Muralla\", which was inaugurated in 1967. In fact, the archaeological site itself, with a total surface of about 60 m\({}^{2}\), was used as a cellar of the hotel. This visit was one of the activities of a congress about fortifications [45]. Until that date, it was commonly thought that the construction of the scarp of the royal moat (1541-1549), which belongs to the structures known as the Portuguese ramparts [46], had removed any remain of the Caliphal Wall. This discovery demonstrated that part of it was applied as a reinforcement to construct the subsequent ramparts. In fact, it was comprised between the scarp and the inner vaults that were built in 1724 [47] under the Spanish domain. The Caliphal Gate and Wall are not the only interesting elements in the site from a historical point of view: Between 2003 and 2009, five campaigns of excavations found Roman remains from the I to the III century A.D., such as an impermeabilized circular structure which was connected to a sewage, a pit excavated in genesis, or pottery [48]. Slags that were used to level the floor during the period of use and construction of the Renaissance structures were also found.  
Figure 3: **(a)** Access to the archaeological site from the bailey. **(b)** Caliphal Gate and Wall after the works of enhancement. **(c)** Detail of the Caliphal Gate.