View looking northwest toward the area where the Herodian Harbor of Caesarea was located. The building on the left (west) is situated on the modern "mole" (breakwater or pier) that is situated on a portion of the southern Herodian mole.
The harbor was built by Herod the Great (37-4 B.C.) and was one of the largest on the Mediterranean Sea. The southern breakwater that eventually turns to the north, was about 1650 feet [500 m.] long while the northern one extended westward about 590 feet [180 m.] long. The entrance to the harbor was from the north. For Josephus' description of the harbor see Wars. 1.408-413 [21.5-7] or Ant. 15.331-341 [9.6].
Extensive underwater archaeological excavations have taken place and have revealed the size of the harbor to be about 25 acres [10 ha.] - the outline of which is also visible from the air - and how it was constructed. Herod built the breakwaters by building wooden box frames, filling them with rubble followed by hydraulic concrete (using a special mix of volcanic ash from Italy). The apostle Paul landed at this harbor at the conclusion of his second missionary journey (Acts 18:22) and possibly at the end of his third as well (21:8). It is probable that his ship departed from this harbor as he set sail for Rome to be tried by Caesar (27:1).