Vasto is the 7th most populated municipality of the region and the 2nd of the province, as well as common leader of the Costa dei Trabocchi and the Vastese area.

It has very ancient origins, dating back to the Frentani people, which in the twelfth century BC founded Histonium, an important seaside village and port of the Adriatic that maintained maritime power between highs and lows over the centuries.

Destroyed by the Lombards, it was rebuilt in the current medieval appearance, becoming an important stronghold during the brief domination of the Caldora and in the Aragonese period, until the proclamation of the short Vasto Republic in 1799, after the secular domination of the D'Avalos family.

The historic center of Vasto is represented by the Caldoresco Castle, the Cathedral and especially by the Palace of Avalos, which houses a complex of museums on local culture, for which from the nineteenth century it was known as "Athens of the Abruzzi".