We followed the Ebre inland from the delta and spent part of a day in Tortosa.
The town straddles the river, with the impressive Castell de la Suda at its top. The castle, now a Parador, has great views of the Ebre and the hills beyond. We stopped at the Parador for lunch on its terrace. The castle structure dates from the tenth century Muslim Caliphate, though the site is thought to have been fortified since Roman times. We saw several castles on this trip – built by Muslims and Christians, who vied for control of this area for centuries.
It has a large gothic and baroque cathedral in the center of town, impressive in scale.