Lahnstein

Lahnstein guards the Lahn's surrender to the Rhine — and once witnessed a king's. Where the gentler river slips into the great one, the town doubles on both banks, crowned by Burg Lahneck on its rock: the castle whose romantic silhouette moved the young Goethe to the poem "Geistesgruß", a knight's ghost saluting the passing boats — Rhine Romanticism in first draft. Opposite, Stolzenfels's Prussian fairy-tale castle answers across the water, and the whole reach belongs to the UNESCO Upper Middle Rhine Valley.

History's sharpest scene played in Oberlahnstein's church of St John: there in 1400 the Rhenish electors declared King Wenceslaus deposed — a crowned head dismissed by committee, with his successor elected across the river at Rhens days later; the town keeps the memory alongside its massive Martinsschloss on the bank, the witches' tower and the old town's timbered corners.

The living calendar is riverine: Rhein in Flammen's fireworks armada passes beneath the castles each summer, the Lahnsteiner blues and theatre seasons fill the halls, and the confluence serves walkers as a junction of great trails — Rheinsteig and Lahnwanderweg meeting above the rivers. A thermal spa quarter adds the cure; vineyards and the Ruppertsklamm gorge add the exercise. Two rivers, two castles, one deposed king: Lahnstein concentrates the Rhine's drama at a single meeting of waters.