Siracusa is situated on a plain in an inlet on the south east coast of Sicily. Siracusa, together with the Pantalica cave necropolis, was declared by UNESCO a World Heritage Site in 2005. Cicero had already defined it as "the greatest and most beautiful of the Greek cities" It is the fourth largest city in Sicily for the number of inhabitants. The town lies partly on the promontory-island of Ortigia and partly on the mainland. The shape of the coastline determines the wide inlet of the Porto Grande, enclosed to the north by the island and to the south by the Plemmirio promontory. The fame of Siracusa is tied to Greek history, when the "polis" commanded the seas, undermining the power of the Carthaginians and Romans until it became the first great empire of the West. There still remains much evidence of this era, such as the famous Fonte Aretusa, a fresh water spring in the heart of Ortigia, linked to the myth of Aretusa and Alfeo, celebrated by many poets and writers and the Galermi Aqueduct.