Maybe it is our predilection for spots to the east of here, but there’s something about reinforced concrete that gets us going. Grenoble’s Perret Tower is another milestone in the story of that marvellous material — this was the first tower built out of the stuff in Europe. The 95m tall piece of octagonal genius, the tower takes the name of its designer, the genius behind the Théâtre des Champs-Élysées in Paris. The tower is one of Grenoble’s most iconic spots, and its upper areas get illuminated during winter.