Barcelona History Museum: prehistoric to the 13th century. The ruins fully preserved in the underground fully show the ancient city of Rome, and the Arabs occupied the evolution of the ancient city of Barcelona until the 13th century. There is a Chinese translator to go with you without worrying about the trouble of language. Tickets 7 euros. Highly recommended. Figure 4 is the drainage system, Figure 6 is the dye cylinder. The translator specifically mentioned that purple cannot be extracted, and the purple required by the nobles needs to be extracted from the shells. This also confirms that in the early years, Moroccan Sovira had a workshop for the Roman nobles to produce purple!