Puig de Sant Andreu in Ullastret is the largest Iberian settlement known in Catalonia and is now considered to have been a true town. It was the capital of the Iberian tribe named as the indikets. in the writen sources.
Remains of sporadic human occupation from the Chalcolithic period have been found at the site; however, the first continuous settlement dates from the beginning of the Iron Age, towards the end of the 7th century BC. The evidence of this comes basically from archaeological material.
The first Iberian town in Ullastret dates from the mid-6th century BC and by the second half of the same century it was fortified with a defensive wall reinforced by seven large towers. During the first half of the 4th century BC the walled area of the town almost tripled in size. It is laid out along the lines of a traditional oppidum, or fortified hilltop town with streets adapted to the slopes and the irregularities of the land.
The settlement went through various phases of rebuilding, the best known of which is the period in which the walls were extended. This entailed major work to prepare the eastern slope of the hill that include the levelling of up to three terraces for new neighbourhoods, as well as the construction of several large houses belonging to aristocratic families. We also know of several important public works, such as temples and cisterns that constitute clear evidence of the community's complex social organisation. The town dominated a large territory in which it exploited the available economic resources, particularly agriculture and stockbreeding as well as mines, quarries, etc. It traded with the other nearby indigenous communities and, via the Greek colony of Emporiae, with Greeks and Phoeno-Punics.
The arrival of the Romans during the second Punic war triggered a transformation in the system of occupation and economic exploitation of the territory, that forced the abandonment of the site at the beginning of the 2nd century BC. In the Carolingian period there was a castle on the hilltop, of which the remains of the wall and towers have been preserved. In the 16th-17th century a chapel dedicated to St. Andrew was built and later a farmhouse.
Some 500 metres to the northeast of the site is Illa d'en Reixac, a contemporary settlement with which it made up a single community.
Puig de Sant Andreu forms part of the Iberian Route.