On this day, no one goes ashore, and nobody minds. The Iron Gates are experienced from the ship's deck, coffee in hand: for about a hundred kilometres, the Danube carves its way between the Carpathians and the Balkans, Serbia on one bank, Romania on the other. It's one of the finest days of sailing in Europe, best enjoyed like a continuous show, with the upper deck's loungers serving as front-row seats; the curtain rises early and doesn't fall until evening.

Golubac, the Opening Act

Upstream, Golubac Fortress announces the gorge ahead. Its 14th-century towers climb in tiers up the slope right down to the water's edge, so close to the river that the ship almost seems able to touch them. Serbs, Hungarians, and Ottomans fought over this stronghold for centuries, since it controlled access to the gorges; now restored, the fortress offers one of the most photographed sights on the Danube. On the opposite bank begins Romania's national park, while on the Serbian side stretches Djerdap National Park: nature frames history the entire way through.