SITES IN PULA
The Roman colony of Iulia Pola Pollentia Herculanea was founded in 46 or 45 BCE, during Caesar's dictatorship, at the site of an earlier Histrian hillfort settlement facing a broad bay with four islets. One of the first steps that followed the founding of the colony was the construction of city walls. The walls encircled the hill and followed the shore. Between 2.20 to 2.50 m wide at the base, the walls were built of limestone rubble masonry and rendered with lime plaster. The walls narrowed in steps to the inside face. The walls included twelve gates fortified with towers. Facing inland were the gates now known as St John's Gate, the Twin Gates (porta Gemina), Hercules' Gate, and the Golden Gate (porta Aurea).
The Hercules' Gate, raised at the dissolution of Rome's Republican Period, is the only one to have survived in its earliest form. It was built using a building technique typical of the Late Republic as a single-arched passage framed by massive blocks of unequal width. The gate is angled in relation to the wall. This alignment reflects millennia of building experience, according to which obliquely positioned entrances force an attacker to expose their unprotected side to defenders. At the top of the arch, a bearded head of Hercules and a club studded with nails are depicted in relief, and next to the club on the left side, an unframed inscription is carved with the names of the first two duumvirs, Calpurnius Piso and Cassius Longinus, Roman senators and members of Caesar's closest personal circle. From the inside, the Hercules' Gate was later reinforced with a defensive corridor.
The Twin Gates are preserved in their renovated Early Imperial Period form. They feature two identical arched passages connected by a unique architectural frame of trapezoidal plan with engaged columns, an architrave, and a richly decorated cornice. The two keystones of the arches have grooves where decorative features were set, likely made of bronze. Like the Hercules' Gate, the Twin Gates were buried under the ruins of the city walls in the 18th century, negating their function.
The Golden Gate was thus named as the primary entrance to the Roman colony. Remains of the city gate with its walls stood until the mid-19th century when they were demolished. The Golden Gate was initially a simple single-arched passage protected by rectangular towers. A triple gate was raised during the reign of Augustus with a wide central passage for chariots and two narrower side passages for pedestrians, and the rectangular towers were replaced by larger round towers. Old engravings show an ascent towards the city entrance in front of the Golden Gate. Although today one descends when approaching the city entrance of the Golden Gate, archaeological investigation has confirmed the original ascent and the existence of outer protective walls built in the medieval period. the Arch of the Sergii was raised towards the end of Augustus' reign to the inside of and abutting the Golden Gate.
The city walls saw multiple medieval remodelling episodes in the course of which a second layer of wall was added to the outside face of the earlier wall, with the footing of this new layer incorporating spolia in the form of parts of Roman era tombstones, column fragments, architraves and cornices, and seating from both the amphitheatre and theatre.
