(“Ruins of Caesarea”), ancient port and administrative city of Palestine, on the Mediterranean coast of present-day Israel south of Haifa. It is often referred to as Caesarea Palaestinae, or Caesarea Maritima, to distinguish it from Caesarea Philippi near the headwaters of the Jordan River. Originally an ancient Phoenician settlement known as Straton's (Strato's) Tower, it was rebuilt and enlarged in 22–10 BC by Herod the Great, king of Judaea under the Romans, and renamed for his patron, the emperor Caesar Augustus. It served as a port for Herod's newly built city at Sebaste (Greek: Augusta), the ancient Samaria of central Palestine. Caesarea had an artificial harbour of large concrete blocks and typical Hellenistic-Roman public buildings. An aqueduct brought water from springs located almost 10 miles (16 km) to the northeast. Caesarea served as a base for the Herodian navy, which operated in aid of the Romans as far as the Black Sea.

The city became the capital of the Roman province of Judaea in AD 6. Subsequently, it was an important centre of early Christianity; (Christianity) in the New Testament it is mentioned in Acts in connection with Peter, Philip the Apostle, and, especially, Paul, who was imprisoned there before being sent to Rome for trial. According to the 1st-century AD historian Flavius Josephus, the Jewish revolt (Jewish Revolt, First) against Rome, which culminated in the destruction of Jerusalem and the Temple in AD 70, was touched off by an incident at Caesarea in AD 66. During the Bar Kokhba revolt of AD 132–135, the Romans tortured and killed the 10 greatest leaders and sages of Palestinian Jewry, including Rabbi Akiba. Caesarea was almost certainly the place of execution of Rabbi Akiba and the others according to tradition (c. AD 135). The death of these Ten Martyrs is still commemorated in the liturgy for Yom Kippur (the Day of Atonement).

After this Caesarea became the capital of the province renamed Syria-Palaestina by the emperor Hadrian. Under the Byzantine Empire it was capital of the province of Palaestina Prima. The church historian and biblical topographer Eusebius (c. 260/264–c. 340) served as bishop of Caesarea. The city declined under later Byzantine and Arab rule. Its port and part of the ancient citadel were rebuilt by the crusaders; the city was successively taken and retaken by Muslim and crusader forces, until finally it was captured and razed by the Mamlūk sultan Baybars I in 1265. Between 1884 and 1948 Bosnian Muslims had a settlement there. In 1940 the fishing kibbutz of Sedot Yam was founded just south of the ancient site; this settlement has built a jetty over the Roman and crusader breakwater. It also engages in agriculture and operates a resort hotel.

Excavations undertaken since 1950 have uncovered a Roman temple, amphitheatre, hippodrome (which seated 20,000), the aqueduct, and other ruins of Roman and later times. Of particular interest is a Roman inscription, found in 1961, which mentions Pontius Pilate, Roman procurator of Judaea at the time of Jesus' crucifixion. This is the first mention of Pilate ever found that can be accurately dated within his lifetime.

Further excavations in the 1970s and '80s, both on land and underwater, gave a clearer picture of the artificial harbour built by Herod the Great. It was probably the first harbour ever constructed entirely in the open sea (i.e., without the benefit of any protective fringing bay or peninsula) and was protected from the sea primarily by two huge breakwaters built of concrete blocks and filled with stone rubble. This spacious harbour, which Josephus compared favourably with that of Athens at Piraeus, was one of the technological marvels of the ancient world and helped make Caesarea a major port for trade between the Roman Empire and Asia.