Their vintage train, The Aberdonian, is pulled by a celebrity engine, 60163 Tornado, a beautiful green steam machine and something of an engineering marvel.
In its time it has played a starring role in the film Paddington 2, and Jeremy Clarkson has shovelled its coal in an episode of Top Gear. It has even pulled the Royal Train.
But while it may look like it is decades-old, Tornado was actually built in 2008 by a team of volunteers.
It is also a bit of a record-breaker, being the only steam train to reach 100mph since the 1960s.
This summer it will be offering passengers a series of unmissable rail trips from Edinburgh, Glasgow and Stirling, for those who love the nostalgia of steam but also the finer things in life.
Old world luxury and fine dining, with some of the best views of Scotland as a backdrop, are on offer as you get on board The Aberdonian from Edinburgh or The Clyde Aberdonian tours from Glasgow.
Powered by just coal and water to create the steam needed to turn the 60163 Tornado’s wheels, expect the smell of smoke and the hiss of steam as you board, before the rhythmic beats of the mechanics and the smoke puffs from the chimney gain speed as you leave the station and start on your journey.
There is a choice of tickets available, starting in tourist class, which offers table seats with unobstructed views and access to the buffet car. Prices are from £99 per person, and there is a four-person family ticket available –
one or two adults plus two or three children – which makes the experience a more affordable day out.
Up a level are the Harry-Potter-esque First Class compartments, or you can opt for the luxury of Premier Dining class, which includes a full Scottish breakfast on the outward journey and a four-course meal on the way home. The onboard caterers specialise in local produce and each meal is cooked fresh and served at the table for the ultimate luxury.
As for the route, from Edinburgh, the train will start by crossing the iconic Forth Bridge before traversing Fife.
From Glasgow and Stirling the route is inland until Dundee, from where both routes follow the dramatic and rugged east coast up to the Granite City, offering spectacular views over the North Sea around each bend.
With a four-hour break in the journey before heading home, you can add on some off-train excursions too.
Passengers can pay a visit to Drum Castle, a 700-year-old estate with tales of Jacobite adventures, which gives a chance to stretch their legs in the Old Wood of Drum, admire the flowers in the Garden of Historic Roses or visit the exquisite 16th Century chapel there.
If you like your trip to be a little more spirited, then a whisky tasting tour of a local distillery could tickle your palate with some of the finest malts from the local area.
Then board the train for a relaxing trip home, with a front-row seat to some of Scotland’s finest landscapes.
There are seven dates available from Edinburgh and two from Glasgow and Stirling, on Thursdays and Saturdays in July, August and September.
Bookings can be made online at 21stcenturysteam.co.uk or telephone 01325 488 215.