Roman remains were discovered in the basement of the Fundação Millennium. A museum section explains the history of the Baixa district from the 7C BC onwards. Visitors can also see the overlaying of buildings from the Pombaline period down to the area's phreatic layer. The site was used as a pottery workshop, a necropolis and then a commercial harbour. Admire also a 3C mosaic and an oven dating from the Moorish period.