When this theater was built, it stood outside the city walls of Roman Tergeste, on the shore. The sea has since pulled back, so today you are looking at a seaside theater that no longer has a beach. The building follows the classic Roman plan. A semicircular seating area, called the cavea, is set into the hillside, and in front of it lies the flat half-circle of the orchestra. The municipal museums of Trieste give its width as just under 65 meters, and they estimate it could hold about 3,500 people. You may come across a larger figure of 6,000 spectators in popular travel writing. I would trust the municipal estimate, since it comes from the city's own civic museums. Dating is also debated. One account places the construction at the end of the first century before the Christian era, with an enlargement early in the second century of the Christian era. The municipal museums point to recent studies that put the building phase in the first half of the first century of the Christian era, with work linked to the reign of Nero. Scholars are still weighing the evidence, so treat the exact decades as open.