That’s a fascinating area of Spain. Two years ago, I spent several days in Cádiz and then drove around to some of these areas. Roman stuff everywhere…heck, Phoenician stuff everywhere.
I lived in Cadiz for about a year. There are remains of a roman settlement nearby called Italica. It was a thriving settlement where even an emperor (Trajan) was born but for whatever reason was abandoned and nobody ever built there again so it's pretty well intact (well, foundations and mosaics and stuff like that, the roofs and walls are mostly gone. When I was there in the 90s you just of drove to it, parked and walked in. maybe had to pay 100 pesetas or something like that, which was like 50 cents at the time. There were no guards, no boundaries or fences, and basically I was all alone, hardly any tourists. You could just sit on a fallen column and look at totally intact ancient mosaics still just sitting there in the ground.
I've been to lots of roman ruins but that place was a favorite because the setting is beautiful and peaceful, there was hardly anyone there, it was ridiculously accessible, and the mosaics and ruins (including and amphitheater) were just very cool.