The abandoned harbourside tunnels that reveal Sydney’s hidden past

The sign at the tunnel entrance reads: Do not disturb – threatened microbats sleep here. Water dragons, as we discovered, also frequent these parts.

This tunnel, part of arguably one of the oldest labyrinths in Sydney, has been off-limits to the public for almost four years over safety concerns. Now, there is a glimmer of hope that it might eventually reopen.

Boom with a view: NPWS Ranger Sam Woodrow at the Beehive casemates at Georges head where heavy guns were positioned. Credit: Nick Moir

You may not even know of the once-secret subterranean network’s existence – and that was the general idea.

The Beehive Casemate battery, named after its shape, was built in 1872 into the sandstone cliffs at Georges Head near Balmoral. The series of tunnels had heavy guns trained on any potential enemy with intentions of entering the Heads and Port Jackson.

The slightly more modern above-ground armoured casement. Credit: Nick Moir

The Herald was invited on an escorted visit to the complex, which is illuminated only by small openings that guns were once aimed through.

Our guide, NPWS ranger Sam Woodrow, pointed out the crumbling remains of wooden gun carriages and the somewhat improvised nature of its construction.

The heavily armoured casemate was built to ward off any potential attackers seeking to enter Port Jackson.Credit: Nick Moir

“The Beehive Casemate was built without military supervision and I think you can tell that once you get down there. There’s a lack of ammunition storage and difficulty in getting that ammunition down to the guns themselves.”

The tunnels were first opened up to the public at the turn of the century. Back in June 2001, a Herald report outlined a restoration programme, describing the underground grotto as “the sort of place where Tolkien’s cave-dwelling character Gollum might live”.

“It’s going to be a great experience for the public when these structures are finally safe enough to be opened,” NPWS assets manager Jenny Faddy told the Herald, saying the Beehive was one of her favourite places in Sydney.

The abandoned tunnels have become a refuge for wildlife, including water dragons. Credit: Nick Moir

But what goes around, comes around. Some two decades later, access was denied, with the tunnels closed after a structural condition assessment in early 2020. Work is ongoing to see if they can be made safe.

An NPWS spokesperson said: “Investigative works are scheduled for completion shortly. However, it is anticipated the tunnel tours will not recommence until all remediation [work] is completed, and the sites are safe to access.”

The Beehive fell into disuse as a military installation after World War II. By the 1950s it was abandoned, visited only by children, the occasional squatter and vandals.

The NPWS took control of the site in 1974, but the battery has remained locked shut. While the structure is regarded as sound, the brickwork – which in places is more than half a metre thick – is damaged by salt, and puddles of water cover the floor and wash over the stone steps.

The underground complex grew in size and complexity over its working lifespan.

Ten years after it was built, in 1882 a second casemate to support the first was built above ground due to both a lack of suitable locations and advances in steel and concrete technology, which ensured some protection against high-velocity shells. The original rangefinder dials for assessing the angle to fire the guns are still visible on the walls.

A plan gives a sense of the scale of the Beehive Casemate.

The new casemate was built in three chambers with magazines, shell stores and lamp passages between them. The construction consisted of mass concrete set with heavy armour plate, with the guns aimed through small apertures, directed by observers in two flanking direction-finding stations.

In 1888, a year after the guns, an additional three 10-inch, 18-tonne guns were installed, the open area was covered over, and a telephone chamber was installed behind the central armament.

Given the popularity of subterranean sightseeing at Sydney’s other World War II sites and below railway stations during the Open weekend in November, if reopened, the Beehive Casemate is likely to have similar appeal for those seeking out the secrets of our city’s past.