Carteia, a footprint of the Roman Empire in the Campo de Gibraltar.

Starting from the 1950s, the Cortijo de Rocadillo in San Roque became the setting for archaeological excavations that gradually uncovered the city of Carteia, a Roman colony founded by the Phoenicians and developed by the Carthaginians, which disappeared in the early Middle Ages.

Located at the mouth of the Guadarranque River, Carteia was already mentioned in Greek and Latin writings before the archaeological remains were found, as stated by National Geographic. The city, overlooking the Strait of Gibraltar and the African coast, occupied a strategic position and engaged in activities such as fishing, salting fish, and pottery.

During the 18th century, drawings and engravings depicting Carteia showed remains of a theater, city walls, and a wharf, which served as the basis for the excavations.

Numerous coins, inscriptions, and other artifacts have been found in the site, including the "huerto del gallo" in 1840, the so-called "marble board" with reliefs of ox skulls (bucrania) and garlands, as well as a strigilated sarcophagus (decorated with symbols in the shape of 'S') discovered in 1927, which is currently preserved in the Museum of Cadiz.

Visitors can currently explore a Punic wall, a Roman temple from the Republican era, a basilical-plan swimming pool, a thermal building, several Roman "domus" (residences), a salting factory, a large building from the time of Emperor Augustus, several Late Roman necropolises (6th century AD), a Roman theater, the Rocadillo Tower (a 16th-century coastal watchtower commissioned by Philip II), and a World War II bunker.