Housed in the basement of the Metropol Parasol, this small museum showcases the ancient finds that were unearthed during excavation of the plaza. Raised walkways allow you to wander between the ruins which date from Seville's Roman era (1st to 6th centuries) and later Moorish period (12th and 13th centuries). Highlights include some 1st century fish-salting tanks and several impressive mosaics.
Note that the entrance is just beyond the Parasol ticket office in the basement. Also, admission is free with a Real Alcázar ticket.