The tunnel was originally meant to be 88 yards (80 m) in length.
However, its actual overall length is 91 metres (299 ft) plus an approach cutting at each end.
The tunnel is straight, unlined and rectangular in section and cut through solid sandstone.
On the walls of the tunnel is etched graffiti.
The majority of graffiti is concentrated near the well-lit southeastern and northwestern entrances.
Each entrance has an open approach cutting that extends from the tunnel.
The northwestern entrance features two interpretive signs, one outlining the history of the tramway and tunnel, the other identifying the use of the tunnel during the Second World War.

Both entrances also feature waist high steel entrance barriers added to the site as part of the Centenary of Federation project.
Neither of the modern interpretive signs or modern entrance barriers are of cultural heritage significance.
The tunnel was originally meant to be 88 yards (80 m) in length. However, its actual overall length is 91 metres (299 ft) plus an approach cutting at each end. The tunnel is straight, unlined and rectangular in section and cut through solid sandstone. On the walls of the tunnel is etched graffiti. The majority of graffiti is concentrated near the well-lit southeastern and northwestern entrances. Each entrance has an open approach cutting that extends from the tunnel. The northwestern entrance features two interpretive signs, one outlining the history of the tramway and tunnel, the other identifying the use of the tunnel during the Second World War.
Both entrances also feature waist high steel entrance barriers added to the site as part of the Centenary of Federation project. Neither of the modern interpretive signs or modern entrance barriers are of cultural heritage significance.
Lahey's Canungra Tramway Tunnel