There’s scenic waterfront running in Giulianova, a coastal town north of Pescara in the Abruzzo region. A palm-lined promenade runs for 12 km from Julia Mare Beach (just south of Giulianova), north to Parco Giochi Bambinopol in Alba Adriatica. There are great views of the Adriatic, numerous beaches along the way, and a festive scene. In some sections there’s a dedicated pedestrian path, while in others the route follows a paved cycle path.

Google Street View

Start at any point along the path!  The southern 9 km parallels Lungomare Sirena, with beachfront most of the way. Then path follows V. Marconi for the final 3 km., ending at Parco Giochi Bambinopol. There’s an additional ~1 km of path turning inland alongside a narrow river bank (often dry).

Note: the beach has soft sand and is not great for running.