It was sophisticated, outfitted with lights powered by a generator.
It was large, its reinforced ceilings tall enough for a person to comfortably stand.
It was dug near the Rexall Centre — the future tennis venue for Toronto’s Pan Am and Parapan Am Games this summer.
And it is not known why a mysterious, bunker-like tunnel was there at all.
Those responsible for building it clearly had some level of expertise in ensuring its structural integrity, police said. "Whoever decided to build this took quite a bit of time."
Police found plywood wall supports, a generator, moisture resistant light bulbs and a sump pump in the chamber.
They also found a rosary with a Remembrance Day poppy nailed on to a wall in the chamber and food and beverage containers.
The mystery tunnel, which the CBC called “sophisticated”, was discovered when a member of the grounds crew saw a slab of corrugated steel and inspected further. He lifted the metal and found a tunnel nearly nine feet beneath the surface. A snow-trodden path led to a nearby tear in a fence, pictures showed. Authorities are holding a news conference today to discuss the tunnel.