Turris Libisonis – Roman Harbour at Porto Torres
Colonia Iulia Turris Libisonis · Porto Torres Roman Harbour
Late Republican to Medieval (46 BCE – 1200 CE)·Roman / Vandal / Byzantine·🇮🇹 Sardinia, Sassari, Italy
About
About Turris Libisonis – Roman Harbour at Porto Torres
Turris Libisonis, Caesar's Colonia Iulia (46 BCE) at Porto Torres, fronts a Roman concrete harbour now partly drowned under the modern port's western basin at 1–2.5 m. Boninu's 1980s underwater survey mapped a 200 m eastern mole of pozzolana concrete with timber formwork impressions, and a buried western quay with horrea foundations now 0.5 m above water but originally at sea level. Cores show harbour mud with Dressel 20 amphorae and 2 m Roman silt. The Riu Mannu river harbour and sea harbour were linked by canal now silted. Harbour abandonment after Vandal c. 455 CE and medieval siltation left mole crest at –1 m visible at low tide.
Why it mattersBest-preserved Roman concrete mole in Sardinia; harbour stratigraphy anchors Sardinian grain trade and sea-level for Asinara Gulf.
Open questions
Mysteries & theories
Mysteries
- 01Whether western quay served river or sea harbour
- 02Chronology of canal linking Riu Mannu to sea basin
Theories
- 01455 Vandal sack accelerated harbour silting visible in Dressel 20 gap
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- 46 BCE (Caesarian colony); harbour moles early Imperial
- Period
- Late Republican to Medieval (46 BCE – 1200 CE)
- Culture
- Roman / Vandal / Byzantine
- Purpose
- Sardinian grain export harbour – annonary port for Rome; naval base for Corsica–Sardinia
- Abandoned
- c. 11th c. (siltation and Giudicato shift to Sassari)
- Rediscovered
- 1841 Taramelli notes; 1984 Mastino colonia; 1988 Boninu underwater mole survey
- Excavation
- Submerged
46 BCE
Caesar founds Colonia Iulia Turris Libisonis
c. 20 BCE
Augustan eastern mole in pozzolana built
1988
Boninu maps eastern mole underwater
On the ground
Structures & features
40.8421° N · 8.3992° E · -1 m · 3 mapped features
Eastern Mole Pozzolana Harbour Arm
mole200 m eastern mole – pozzolana concrete with timber impressions at –1.5 m
40.8425° N · 8.4005° EWestern Quay and Horrea
quayWestern quay with horrea foundations – warehouse block at +0.5 m
40.8415° N · 8.3970° ERiu Mannu Canal and Roman Bridge
canalCanal linking river harbour to sea – Roman bridge over Riu Mannu
40.8390° N · 8.3985° E