THE world's oldest steam locomotive of its kind has rolled into Dublin to celebrate its 150th birthday.
The historic Princess took a ferry from Wales, where it used to haul slate trucks from quarries, to go on display in Heuston station.
Tourism chiefs are hoping it will attract visitors from Britain to a heritage railway tour as part of this year's Gathering.
Built in London in 1863 to service the Snowdonian quarries, it was one the first steam locos ever built for a narrow-gauge line.
Since going out of service in the 1940s, Princess has been part of the Ffestiniog Railway Museum in north Wales, where it was painstakingly restored.
Public Transport Minister Alan Kelly said the steam engine was an important part of our railway heritage.
"The Princess represents a piece of our transport history," he said. "For enthusiasts – and indeed for the general public – it is great that this locomotive has come to Dublin."
The locomotive will be on display at Heuston until July 24.