How Could Territory of Atlantis Be an Island Extending Gibraltar to Libya & Italy Outside Along Atlantic Coast Too?

When people call Atlantis an island, they are right about the city of Posidon, three concentric canals with the city in the center, yet the territory of Atlantis wrote Plato was extended from the Pillars of Hercules (Gibraltar) to Libya and the Tyrrhenian Sea, outside Gibraltar as well, clearly not an island, as the word nesos to describe the city and the greater territory can mean island or peninsula (of western Europe).