THE ONE LANDMARK
Designed as a showpiece during the coal industry's early 20th-century zenith, the Zollern is strikingly attractive as coal mines go. It has now been turned into an industrial museum and cultural centre – and is a great place to get a taste of what life in the mines was like. The permanent exhibition doesn't shirk the tougher subjects such as forced labour during World War II. See lwl.org
THE ONE SPORTING PILGRIMAGE
Dortmund is a football city, and thus the rightful home of the German Football Museum. Plenty of the content is as expected – biographical detail on players and managers, boots and balls from major matches – but it also has plenty of fun touchscreens to play with. These range from quizzes about football teams to playing the referee and having to blow the whistle at the right moment. Anglophiles will be greatly entertained by the big – and bitter – section devoted to whether one of England's goals in the 1966 World Cup Final should have been disallowed See fussballmuseum.de
THE ONE TREE
Dortmund's gigantic Christmas market is one of the best in Germany, spreading out over the pedestrianised city centre without ever feeling uncomfortably crowded. The centrepiece is the world's largest Christmas tree, which is actually 1700 separate fir trees stacked together to create the illusion of a single 45-metre-tall monster.
THE ONE MUSEUM
The enormous DASA Working World Exhibition has the potential to be exceptionally boring – and, yes, there is a section that tells you how to safely lift a heavy box. But it gets rather cool when you can drive truck simulators, play inside a helicopter, sit at the controls of an air-traffic control tower and watch high-tech robotic arms in action. It is several times more fun than it has any reasonable right to be. See dasa-dortmund.de
THE ONE PRISON
As soon as you enter the Steinwache, it's obvious what it used to be. Cells line either side of a central atrium, with nets hanging over the gap. This former prison was notorious for the torture of prisoners during the Nazi regime, and is now a museum dedicated to the period from 1933 to 1945. It pays particular attention to the rise to power via controlling the press and co-opting big business. See ns-gedenkstaetten.de/nrw/Dortmund
THE ONE RESTAURANT
Once a brewery, Dortmunder U has been turned into a flashy arts complex. The Emil restaurant at the back has a sprawling outdoor terrace, plus showy chandeliers and long banquettes inside. Grilled meats are the star, with a great show made of explaining the provenance of the steaks, whether from Canada, Australia or Uruguay. Mains cost from about €25. See emil-dortmund.de
THE ONE PARK
Sprawling Westfalen Park is dominated by the Deutsche Rosarium, which breeds rare rose varieties, in a range of colours from white to near-black, heading between pinks, yellows and reds on the way. There are more than 2600 varieties of rose in the beds that flank the footpaths. See rosarium.dortmund.de
THE ONE HOTEL
A short walk from the station and with lots of freebies thrown in – biscuits, jelly bears and mints among them – the NH Hotel gets a lot right. The spacious rooms would be called suites elsewhere, and the 360-degree spinnable TVs and black-and-white street photography emblazoned on the shower walls are very cool. Expect to pay from €139. See nh-hotels.com
THE ONE GALLERY
Dortmund should really be treated as part of the Ruhrgebeit, a conurbation of cities well connected by public transport. The Ruhrgebeit is home to several of the most impressive tent pegs on the European Route of Industrial Heritage. These include the Gasometer in Oberhausen, where 360-degree art exhibitions are held in a 117-metre-tall gas cylinder. See gasometer.de
ONE MORE THING
This is an atypical German city where not everything's possible by public transport – and it's arguably best tackled as part of a road trip with a hire car.
David Whitley travelled at his own expense.