We arrived in one of Croatia's oldest continuously inhabited cities, where layers of history stack beneath your feet. This was ancient Iader to the Romans, their colony that thrived from the 1st century BC through the 3rd century AD. Walking through the old town peninsula, I found myself standing in the Roman Forum – the largest on the eastern Adriatic coast – still serving as the city's living room two millennia later. Column capitals catch the morning light while locals sip coffee where senators once debated.

St. Donatus Church rises beside the forum like a stone spaceship – 9th-century Byzantine architecture built directly on the Roman ruins, its circular walls incorporating fragments of the ancient columns and capitals. The church doesn't hide its Roman heritage; it celebrates it, embedding the past into every stone. Standing inside, I could trace the Roman lettering on recycled capitals now supporting medieval arches.

Then we discovered why Zadar belongs to the 21st century as much as the ancient world. At noon we sat on the marble steps of the Sea Organ – architect Nikola Bašić's 2005 marvel where waves push air through pipes beneath the stone, creating random haunting chords that shift with every swell. Children danced to the "music" while we closed our eyes and let the Adriatic compose a private symphony. Each wave wrote a new chord progression, never the same twice.

We had lunch at Foša – black cuttlefish risotto and fresh sea bass grilled with blitva while watching yachts parade past the ancient walls. As afternoon softened into evening, we walked to Bašić's second installation, the Greeting to the Sun – a solar-powered circle of photovoltaic glass panels that erupts in wild colors at sunset, synchronized to the organ's notes below.

Alfred Hitchcock once declared Zadar's sunset "the most beautiful in the world," and standing there as the sun melted into the Adriatic while the Sea Organ played its wave-song and the Greeting to the Sun blazed in response, I understood exactly what he meant. The pros: compact, innovative, genuinely unique, and layered with millennia of continuous habitation. The cons: small, so one ship fills it – but the installations work even better with an audience.