The City of Halifax has a rich history filled with stories that inspire the imagination. Folktales have been passed on of shipwrecks, ghost stories and threats of war.

But one mystery that has yet to be solved is what lies beneath the city’s streets.

Below the floorboards of the Halifax Club lies an opening that leads to a passage which is said to have linked to Citadel Hill.

Parks Canada spokesperson Hal Thompson says construction crews have uncovered tunnels in the past, but only one linked to Citadel Hill.

“There’s lots of rumours of different tunnels under the city that might link up to the Citadel,” says Thompson. “Of course, we don’t have any evidence that they do.”

Barbara Hinds was a reporter for the Chronicle Herald in 1973 when the construction crew was working on George Street.

Hinds says the road collapsed and the cavity revealed a tunnel, so she jumped in.

“It was quite thrilling actually, to be in such a structure,” says Hinds. “It led up to Citadel Hill and the other extremity was towards the harbour, Halifax harbour.”

The idea that there are secret tunnels under the city is compelling folklore but answers to questions, such as who built them and what they were used for, is still just speculation.

“Did the army build them for defensive reasons? When would they have used them? What situation would've required the use of these secret tunnels?” asks Thompson.

Hinds says Scottish stonemasons built the tunnels for the military - information she learned through a letter, now lost.

“They were all sworn to secrecy,” says Hinds. “This woman who wrote to me after the story was published, she said she was the granddaughter of a Scotsman who helped to build a tunnel from Citadel Hill down to the waterfront. That was quite a revelation.”

“They do have a military appearance,” says Thompson. “But, of course construction methods in the 19th century were fairly common across all contractors and so on. They built things the same way.”

Parks Canada has disproved one rumour.

“Ground penetrating radar of the harbour floor shows absolutely no evidence of a tunnel linking the harbour, the shore, with Georges' Island,” says Thompson. “It's very deep there. If there was a tunnel that had collapsed you'd still see that on the radar.”

With files from CTV Atlantic's Sarah Plowman