Arzew or Arzeu (Arabic: أرزيو, ʾArzyu) is a port city in Algeria, 25 miles (40 km) from Oran.

][clarification needed] Nearby Bethioua was the Portus Magnus ("Great Port") under the Roman Empire, although the name was used on Arzew's coat of arms under French colonial rule.

[1] Portus Magnus was destroyed during the Vandal conquest of northwest Africa in AD 429 or 430 but saw some use by the Byzantines after their 6th-century recovery of the area, leaving some Christian remains.

The Roman relics remaining at Bethioua into the early modern period were mostly removed to the provincial museum at Oran during the 19th and 20th centuries.

[4] After the independence of Algeria in 1962, Arzew became an important port and industrial area, home to a refinery exporting LNG (liquified natural gas), as well as a fleet of small fishing boats to work the local waters.