Ian Young, owner of Ness Islands Railway, is selling up the attraction he created 35 years ago due to ill health,
The miniature railway, which includes a station, engine shed, shop and an 0.8mile track which runs through a display of exotic animal models, can be found at Whin Park on the outskirts of Inverness.
The family hopes to find a buyer who will keep the railway, which can attract up to 600 visitors a day, in the city.
Mr Young, 75, a former Air Training Corps officer and professional railwayman, told the Press and Journal:
“I’ve recently received a diagnosis which means it will be impossible for me to continue.
“My son Barry and daughter Julie are successful professionals with their own children and busy careers. Both live many miles from Inverness and, as a result, there’s no possibility of them being able to take over.
“I’m looking for somebody else to preserve the tradition.”
The railway comes with all rolling stock, track, buildings, 140ft bridge, tools and gifts and souvenirs.
Full details are available online at nessislandsrailway.co.uk