Sydney, Australia, the most populous city in the country, as well as the capital of the state of New South Wales, is perhaps most easily recognized by its famous opera house, an iconic work of architecture which opened to the public in 1973. Yet Sydney-siders will be the first to tell you, there is so much more to the city:  parks, beaches, museums, the Royal Botanic gardens and an impressive range of markets.

Sydney was the site of the 2000 Summer Olympics and has enjoyed, in recent years, an influx of tourists reaching toward nearly three million. Visitors stream in on flights to Sydney through Sydney Airport, one of the oldest airports in the world, while the city's historical background, as part of a colony of the British Empire until 1901 and an essential factor in the Pacific theater during World War II, ensures Sydney a suitably notable place on the list of great cities of the world.

Yet there is a shady underbelly to Sydney – but don't worry, it's a lot less mob wars and a lot more underground lake. In fact, if you're visiting the city, then consider calling on the disused tunnels which sprout off St. James Station – underground. Creepy, cool and let's face it, we'd like to be convinced they're haunted; the abandoned tunnels are a fascinating way to immerse yourself in a darker – literally! – side of Sydney.

St. James Tunnels: A Brief History

The St. James Station was created in the 1920s and was intended as a major interchange with the eastern suburbs railway line, which ran from the Bankstown, East Hills and Illawarra lines. Four platforms were built in all, but two were destined to remain unused and the tunnels which were constructed for them are called "stubs," since they extend for roughly 250 meters to the north under Macquarie Street, and to the south reach the intersection of Liverpool and College streets, before abruptly ending. Because planners and politicians couldn't agree on the north/south route, the tunnels remained unfinished and most likely will, over 80 years later.


Everything but Train Rides

While the tunnels may never have seen a single underground train passenger, they have nonetheless been used over the decades. It is well-known that in the 1930s, scientist and writer Raymond Mas used the tunnels as a farm in which to grow experimental mushrooms; in the year he used the tunnels, Mas produced 10,000 pounds of mushrooms per month.

Perhaps more significantly, the abandoned St. James tunnels were used as both air raid shelters and an operations bunker by the No. 1 Fighter Sector RAAF during World War II. The north-running tunnel was intended to keep civilians safe in the event of a bombing and the ruins of concrete walls that were built to withstand explosions (and thus stop the force of explosion from spreading to the next chamber) remain, as the soldiers who were charged with tearing down the walls left them behind. There is also 70 year old graffiti in the tunnel, another interesting remnant of the World War II soldiers who worked in the tunnels and left their regiment number and the date, most in 1942.

The operations bunker was located below the road called Shakespeare Place, which runs between the State Library and the Royal Botanical Gardens; the bunker was accessible by a wooden staircase. A fire destroyed that in the 1960s. From that bunker RAAF was connected to radar stations, weather signals, air raid sirens and blackout shipping, among others. And just like we've seen in the movies, a large table sported a map of the New South Wales coast and was used to help plot aircraft movements.


The Lake and "The Tunnel"

At some point after the war, the north-running tunnel flooded, creating an underground lake some ten meters wide, five meters deep and one kilometer long. Enterprising locals have used it as swimming hole and CityRail employees insist the lake is home to an albino eel named Eric. Well, every underground lake needs its monster – and this was apparently what Carlo Ledesma, director of the 2011 horror flick "The Tunnel," thought. His movie, set unofficially and filmed partially in the abandoned St. James tunnels, depicts a journalist's encounter with some unseen but violent creature that lives in the depths below. It's just fiction, of course, but – it's just creepy enough down there to make you wonder, isn't it?

This article was written by Jack Pearson.Jack is a freelance writer and travel consultant who has been helping people plan great vacations for over four years.