Mannheim is famous for its quirky – indeed, unique – chessboard street layout. The city centre, which measures 1.5km by 1.5km, is divided into four quadrants by two perpendicular, largely pedestrianised shopping streets, the north–south Breite Strasse and the east–west Planken. At their intersection is the grassy Paradeplatz, with a fountain in the middle.

The streets don’t have names. Instead, each rectilinear city block has an alphanumeric designation. Starting at the Schloss, as you move north the letters go from A up to K for blocks west of Breite Strasse and from L to U for blocks east of it. The numbers rise from 1 to 7 as you move away – either east or west – from Breite Strasse. The result is addresses such as ‘Q3, 16’ or ‘L14, 5’ (the latter numeral specifies the building) that sound a bit like galactic sectors.