A pulley wheel from Edinburgh's original tram network has been uncovered - nearly 100 years after it was last used.
Archaeologists are celebrating after the wheel was discovered during work to extend the current line to Newhaven.
It is believed to date from around 1888, when the city's original horse-drawn tram system was switched to being powered by cables running under the rails to pull the trams along.
The find on Leith Walk near its junction with Pilrig Street is believed to be close to the so-called "Pilrig muddle" where passengers were forced to change from Edinburgh's trams to Leith's separate electrically-powered system.
The wheel is thought to have been decommissioned when the city's trams were electrified in 1922.
A similar wheel was discovered during non-tram excavation work around ten years ago at nearby Shrubhill but left in place and re-covered.
City archaeologist John Lawson said experts from Guard Archaeology would investigate and record the find in the next week.
He said: "This is a very important and interesting discovery.
"It is part of the original cable winding mechanism. We will then try to remove it for safekeeping."
No decision has been taken about whether it will be put on public display.
Tram fan ACamerumer, who posted pictures of the find on Twitter, said: "I'm hoping that they could be dug up, re-built and put somewhere along the route, or reinforced glass put on top so people could look down and see some historical engineering."
Paul Tetlaw, a rail expert at sustainable transport campaign body Transform Scotland, said: "It's a wonderful find so let's hope it can be preserved as part of future tram works."
Transport enthusiasts on Twitter commented that the forgotten wheel should be used as a feature on the route when the new line opens in Edinburgh.
