Passengers taking the Metro today may have spotted a special visitor on the train.
Digby the miniature horse has been in the region to prepare for his new life supporting partially sighted Helena Hird, who lives and work in London.
He can accompany blind people just like a guide dog, and paid a visit to Metro to help him get used to the sights and sounds of travelling on a transport system.
Nexus, which owns and manages Metro, opens up its system to train guide dogs - so Digby the guide horse was also welcomed with open arms.
Digby's day out helped him experience trains, stations, ticket gates and lifts. He was supervised along the way by Metro staff.
For the occasion, he wore a harness, special pants and booties to protect his hooves.
Chris Carson, Metro Services Director, said: “We were thrilled to help out Digby the guide horse with his training. We’ve loved being involved in such a wonderful and heart-warming story, and our customers have loved it too.
“We do a lot of guide dog training on Metro, but a guide horse isn’t a sight that we’ve ever seen. It’s brightened up everyone’s day.
“Digby took all the sights and sounds of the Metro system in his stride. I hope that the training has been of great benefit to Digby and his owner ahead of his big move to London.”
Katy Smith, who runs KL Pony Therapy in North Yorkshire, is the proud owner of 20-month-old Digby and has trained him up to become a guide horse.
She has thanked Metro for providing the "ideal" setting for Digby's training day.
Katy added: “He’s such a lovely little horse. When I first got him I knew that he had something special and that he had what it took to be a guide horse.
"He’s brilliant at following all of the commands, just like a guide dog can. He has the intelligence, the ability, and the personality.”
Digby's new owner Ms Hird wanted a horse to help her with a genetic sight condition, rather than a guide dog, because horses live for much longer.
Unlike dogs, they can live for as long as 45 years.