It's the near-forgotten tunnel that's only really known by Edinburgh locals who are able-bodied enough to scramble underneath it.
Situated beneath the Union Canal between Lanark Road and Redhall Park is an eerie passageway that almost looks as if it was built for Hobbits.
Muddy and partially hidden by foliage, the towpath tunnel is virtually unknown to most of the walkers in the area, who generally opt for the modern concrete footbridge that traverses both Lanark Road and the canal.
READ MORE: The Edinburgh factory immortalised in Hollywood blockbuster Titanic
But there was a time when the little tunnel provided the only means of getting from one side of this part of the canal to the other without getting your feet wet.
It's unclear exactly when the tunnel was built, but it could date from 1822 when the Union Canal was completed.
Sign up to our Edinburgh Live nostalgia newsletters for more local history and heritage content straight to your inbox
Whatever the case, it certainly wasn't constructed with ease of use in mind. As you enter through the south portal, the cramped passageway reduces greatly in height, forcing you to crouch down for a good six or seven metres until you're through the other side.
The towpath tunnel was recently the subject of a conversation on the Edinburgh Past and Present group on Facebook.
Sharing a photo of the tunnel, James Cassidy asked fellow group members if they knew where it was, with only a small fraction of people managing to answer correctly.
READ NEXT:
Abandoned former asylum near Edinburgh saved after council announce purchase order
The oddball venture that saw abandoned Edinburgh tunnel filled with mushrooms
Remembering when you could take your car from Edinburgh to Fife by ferry
Seven famous Edinburgh landmarks and how much they'd cost to build today
Incredible drone footage shows East Lothian's abandoned village trapped in time
