The airport tunnel was a significant engineering feat when it was built in the mid-1960s.
A Leader report in 1965 said the tunnel, which was designed to carry traffic on General Holmes Drive underneath the airport runway extension into Botany Bay, was "one of the biggest road tunnel projects in Australia".
It would be about the same length as the Cahill Expressway tunnel but wider and with a concrete roof three feet (a metre) thick.
The tunnel, which opened in 1967, was built six feet (two metres) below water level and "special precautions have been taken to prevent flooding or seepage".
The entire area was sand as a 1965 construction photo shows.
Another photo from that era shows a bus making its way past sand dunes on the edge of General Holmes Drive, where Cook Park is today.
General Holmes Drive was constructed as a two lane road in 1919 and duplicated in 1951 with a new bridge built over the Cooks River, which was diverted to allow the airport to expand.
The road was named after Major-General William Holmes, a citizen soldier and secretary of the Metropolitan Water, Sewerage and Drainage Board, who became the most decorated soldier in the First World War.
R W Rathbone, in his history of Brighton-Le Sands, The Suburb that Grew from the Sand Hills, said Holmes joined the Citizen Military Forces in 1872 as a bugler at the age of 10 and by 1903 was the commander of the 1st Regiment of the New South Wales Military Forces.
"He served in South Africa during the Boer War and was awarded the Distinguished Service Order for his daring and his courage.
"At the outbreak of the First World War, he was placed in command of the Australian Naval and Military Expeditionary Force and was given the task of seizing German New Guinea.
"Having accepted the German Governor's surrender, he was posted to Gallipoli where he supervised the evacuation of the Australian troops in December 1915 with remarkably few casualties.
"His next appointment was to command the 5th Australian Brigade at the battles of Pozieres and Flers in northern France.
"In January 1917 he was promoted to Major-General and given command of the 4th Division.
"On 2 July 1917 he was escorting the NSW Premier, William Arthur Holman, on an inspection of the battlefield at Messines when he was mortally wounded by shellfire and died on his way to a field hospital."