Colonel William Light had buoys placed at the entrance to the Port River soon after its discovery. It took another 30 years of agitating before an adequate light was placed at the entrance. In 1866 work began on building a 50 feet square platform, some 20 feet above high water. From this a metal column would rise with the light at the top.

It was a difficult task sinking the metal column through the accumulated and compacted shells and grit on the seabed and eventually a caisson was forced down. The whole work was supported by a maze of wooden piles. The light was finally exhibited in 1869.

It was regretted that the original tender for a screw pile light had not been accepted. In 1874 the light was rebuilt and a more powerful light was exhibited.

In 1901 the column was removed from the entrance to the Port River and erected on South Neptune Island. The light was transferred to the new light tower on Wonga Shoal off Semaphore.

The light at the entrance to the river was temporarily replaced by a buoy with an occulting light until in 1904 a fixed light was placed at the base of the old lighthouse structure.

The tower from South Neptune Island was erected at the end of Commercial Road, Port Adelaide in 1986, and is part of the South Australian Maritime Museum.