The Roman emperor Caesar Augustus awarded the city of Samaria to Herod the Great in 30 B.C.E., who rebuilt it and renamed it Sebaste in honor of Augustus (Sebastos is Greek for Augustus). Most of the impressive archaeological remains still visible at the site are from this Roman-period Sebaste. Perhaps the most famous is the colonnaded east-west street (pictured).

The summit of the hill served as the Roman acropolis. Here Herod built the Augusteum, which consisted of a temple with a large forecourt (the surviving steps are actually from a second-century rebuilding of the temple by Septimius Severus). A temple of Kore (also known as Persephone, queen of the underworld) stood on the slope of the acropolis.

Also on a lower terrace, the remains of a theater were uncovered, including several rows of seats, paving from the orchestra, foundations from the stage, and architectural details from the façade. The external diameter of this semicircular theater measured nearly 215 feet (65 meters).

The heart of Sebaste lay in the fields below the acropolis. This was where the forum was located, where people came to take care of their day-to-day affairs. It was 420 feet wide and 237 feet long, and it was adjoined by a basilica that has been only partially excavated.

The city was protected by a turreted city wall 2.5 miles long. Subterranean aqueducts brought water from springs to the east. The site continued to be occupied into the Byzantine period, and tradition identifies it as the burial place of John the Baptist.