Breakwater
A 13.6-kilometer (8.5 mi) long breakwater stretches across most of the bay, with two openings to allow ships to enter the port areas behind it. The initial western section of the breakwater, called the San Pedro Breakwater, was constructed between 1899 and 1911 at San Pedro; the Middle breakwater was completed over the next twenty-five years, and the Long Beach breakwater was finished after World War II.
Read more about this topic: San Pedro Bay (California)