The traveller who follows the Danube upstream through central Europe will discover many iconic buildings. In Budapest, there is the striking Gothic Revival Országház, the Hungarian parliament building which was conceived as a symbol of national identity. Moving upstream there are buildings which speak of Catholic power: the great basilica at Esztergom in Hungary and the huge baroque abbey at Melk in Lower Austria.

In the roll call of fine buildings which grace the Danube Valley, few can match the mock Greek temple at Donaustauf as an expression of secular authority with a nod to religious conviction. Modelled on the Parthenon in Athens, the Walhalla memorial is an idiosyncratic hall of fame which honours the greatest Germans who ever lived — generally favouring worthies of Christian persuasion. Catholic credentials were especially helpful in securing a place on this Bavarian fast track to immortality. Martin Luther didn’t make the first cut and only secured a place in this German pantheon well after it was inaugurated by King Ludwig I in 1842.