How Terracina was built and evolved over time

Two Roman structures define Terracina, and both were responses to the same terrain.

The first is religious and goes up. The Temple of Jupiter Anxur stands on the sea-facing summit of Monte Sant'Angelo at 226 metres above sea level, towering over the historic centre — a temple to the city's tutelary god placed where it could be seen from the sea and from the plain.

The second is civil and goes down, and it took four centuries to get right. The Via Appia, built in 312 BC, at first crossed the hill behind the promontory by a steep ascent and descent. In 184 BC the censor Lucius Valerius Flaccus tried an embankment thrown out into the sea. It was probably only early in Trajan's time, AD 98 to 117, that a cut through the rocks at the foot of the promontory solved the problem.

That cut is at Pisco Montano, the imposing limestone cliff of 128.8 metres detached from Monte Sant'Angelo, and the Romans measured their own work on it: the depth is marked on the vertical wall at intervals of ten Roman feet, with the lowest mark, about a metre above the present road, reading CXX — thirty-six metres.

Between temple and cut, the city itself develops from a spur of the same mountain, with the beaches spreading either side.