King George V Park is one of Edinburgh’s hidden spaces. Maybe not an obvious place for casual visitors because it’s just a local park – a green space for local folk who don’t have their own gardens, and a place for children to play. And it’s also, bizarrely, the site of a disused railway tunnel that even Edinburgh residents often don’t know about.

To get to King George V park, start at the Canonmills branch of Tesco. With the store behind you, cross the busy carpark access road, and find a fine path which follows the route of an old railway line. Turn left and pass through a short tunnel, attractively graffitied with colourful designs. On exiting the tunnel, go straight ahead through a brightly-painted gate, passing a children’s playground on your right, and come to a slightly dejected-looking basketball court.

The archway ahead of you forms the entrance to Scotland Street Tunnel. The tunnel has a strange history. Opened in 1847, it was closed just 21 years later.

It hasn’t been entirely disused all that time. Shortly after the tunnel was closed, the Scottish Mushroom Company set up business, using the tunnel as a mushroom farm. That lasted until 1929, and the tunnel fell out of use again until being converted into an air raid shelter in the second world war.

Since then, the tunnel has been completely inaccessible for the general public, although a YouTube video from 2023 gives a comprehensive look at the interior. It would be good if the tunnel could be reopened, as the 1km length could provide a safe and car-free walking/cycle route between Waverley and Canonmills. Until then, we can dream.