Roman Aqueduct

Just outside Olbia, this Roman aqueduct and water system is one of Sardinia's more underrated ancient sites — a genuine relic of how seriously the Romans engineered their infrastructure even on an island. You can walk right up to the ruins and get a real sense of the scale, though watch yourself near the road on one side since traffic doesn't always slow down. It's the kind of place that sneaks up on you — easy to pass by, but worth a proper look if ancient history is your thing.