Lifelong transport enthusiast Gareth David puts the Shrewsbury signal box at the top of his personal top 20, saying it is the "biggest – and simply the best."
He adds: "For the sheer joy of appreciating mechanical signalling in action, there can surely be no better place in Britain to visit than Shrewsbury.
"Here, no less than three major signal boxes can be seen from the station platforms. The majority of signalling remains mechanical and there is not only a curious mix of upper and lower quadrant signals, but you will find two extremely rare wooden arms, the likes of which I have only ever seen at Liskeard and Droitwich Spa."
Book author Gareth says that while it was originally intended to replace all mechanical signalling by the millennium, numerous outposts of the old ways remain.
His book, Britain's Last Mechanical Signalling, is a loving description of the places where the once-familiar semaphore signals have not yet been replaced by coloured lights.
"At the time of writing there are still sections of route where there are significant outposts of mechanical signalling to be viewed and appreciated," he says
He highlights among others the Marches line northwards from Newport in Wales to Shrewsbury, where he says there are a dozen surviving boxes, from Little Mill Junction near Abergavenny, to the "big daddy" of mechanical signalling – Severn Bridge Junction at Shrewsbury.
Despite the continuing upgrading of the signalling system he says that, according to his analysis, as of October 2017 there remained about 200 locations across Great Britain where there are signal boxes controlling at least one semaphore.
His researches have taken him around the country, by train of course, to visit the places where the traditional system is still in operation.
He says that Shrewsbury, with the world's largest mechanical signal box at the Severn Bridge Junction, and the nearby Abbey Foregate signal box, has Britain's finest signalling location.
Gareth says Severn Bridge is a 1902 LNWR box with 180 levers which has been the largest mechanical box in the world since the closure in 2011 of the 191-lever box at Spencer Street in Melbourne, Australia.
Other feathers in Shropshire's cap include having the UK's last working lower quadrant distant signal on the Marches line just south of Shrewsbury, and controlled by the Sutton Bridge Junction signal box.
Britain's Last Mechanical Signalling is published by Pen & Sword and costs £30.