Pharos Portus
About
Monumental lighthouse modeled on the Pharos of Alexandria, built on an artificial mole-top island at the seaward mouth of the Claudian basin as part of Claudius's harbor project; functioning and celebrated on Nero's sestertii minted for the harbor's 64 CE dedication (obverse/reverse harbor scene showing the lighthouse between the two curving moles). A functioning aid to navigation still in active use in 117 CE, guiding shipping into both the Claudian and the newer Trajanic basin. Later depicted again on coinage under Trajan and subsequent emperors. Exact structure position is reconstructed from excavation on the mole between the two basins; treat this point as approximate (±200-300 m) pending direct access to Portus Project survey plans.
What happened here
The fire burns at the top all night and is visible for miles from a coastline that otherwise gives a pilot nothing to steer by. Fuel — wood, or oil where wood is scarce — is carried up an internal ramp or hoisted, and a crew lives on site to keep the fire fed and the reflecting surfaces clean. A tower on a mole doubles as a harbour marker and a breakwater. Mariners complain that a steady light at sea can be mistaken for a low star, and that is a real hazard. By day the tower is a landmark instead. It appears on coins and on the mosaics of shipping agents, because a port with a lighthouse is advertising that it can be entered at night.
Sources
Roman Maps shows the empire frozen at 11 August 117 CE, the day Trajan died — its moment of greatest territorial extent. Explore the full map →