Probably Greece.

With the deciphering of Linear B, scholars have discovered that the Mycenaeans spoke a language that was already close to Ancient Greek, though their syllabic script expressed it a bit differently from what we are used to. These texts go back to the 15th century BC. Since there are no cataclysmic events in what is archaeologically known as the Middle Helladic period (c. 2000-1500 BC), despite ancient Greek stories about a supposedly newly arrived Minyan people, it wouldn't be too strange to suppose that people a further 500 years back would already have spoken a form of proto-Greek.