Built in 1907, the Imperia car factory still dominates the village of Nessonvaux. It was established in the valley of the Vesdre by the Belgian engineer Adrien Piedboeuf who invented one of the first hybrid car engines as well as the electric cigarette lighter.
The factory originally tested its cars on local roads, but people started to complain.
The owner then came up with the original idea of building a test track on the factory roof, a few years before Fiat built its famous rooftop track in Turin.
The factory finally closed in 1958, leaving an impressive main building in the style of a mediaeval castle. Now there are just 34 Imperia cars left in the world, including four cars in a small museum a few kilometres down the road in the village of Fraipont.
The fries shop Frites Imperia in Rue Docteur Heuze has nostalgic photographs on its walls and the Rue Heid Mawet leads to a viewpoint where you can look down on the race track.
Meanwhile, the former factory is currently being converted into apartments. It isn’t clear how much will survive of this historic building where the Belgian car industry was shaped.
Derek Blyth’s hidden secret of the day: Derek Blyth is the author of the bestselling “The 500 Hidden Secrets of Belgium”. He picks out one of his favourite hidden secrets for The Brussels Times every day.