Ancient Roman aqueduct in Caesarea Maritima, Roman water conveyance structure at Mediterranean coast, Israel.

The aqueduct of Caesarea Maritima consists of two parallel channels, Channel A and Channel B, built of kurkar ashlar blocks with lime-based concrete walls, plastered inside and out. Channel A, 115 cm high and 70 cm wide, runs on a continuous stone wall that becomes a series of semicircular arches where the ground drops; Channel B, 140 cm high and 90 cm wide, was attached to its northern side. The aqueduct stops 900 m north of the city, cut by a marine inlet.

The higher channel was probably built by Herod when he founded the city, and the lower channel was added as the population grew. The lower channel was built in 130 CE for Hadrian's visit to Judaea, as eleven inscriptions record, ten of them Latin texts of the Roman legions. A Greek inscription from 385 CE records a repair in the Byzantine period. The system served the city until the Mamluk sultan Baybars destroyed Caesarea in the 13th century.

Roman soldiers carved inscriptions and legion symbols into the aqueduct's walls, leaving traces of their presence along the structure near Beit Hanania. These markings reveal which military units worked on this project and how much the Romans valued such engineering achievements.

The ruins are accessible along Caesarea's beach, with parking facilities nearby and no entrance fee to view them. Visitors can examine the remains directly from the beach area and take photographs.

The aqueduct's slope was minimal, dropping only 16 cm per kilometre, which let water flow gently from the springs to the city. Channel A stands without repairs to this day, while Channel B, built of softer stone, shows many later patches.