Asia Minor
In 334 BC, Alexander crossed the Hellespont into Asia. It took over one hundred triremes (triple-banked galleys) to transport the entire Macedonian army, but the Persians decided to ignore the movement.
In these early months, Darius still refused to take Alexander seriously or mount a serious challenge to Alexander’s movements. Memnon of Rhodes, the Greek mercenary who aligned himself with the Persians, advocated a scorched earth strategy. He wanted the Persians to destroy the land in front of Alexander, which he hoped would force Alexander’s army to starve, and then to turn back. The satraps in Anatolia rejected this advice, considering it their duty to defend their land. Eventually, with Alexander advancing deeper into Persian territory, Darius ordered all five satraps of the Anatolian provinces to pool their military resources together and confront Alexander. This army was guided by Memnon, while absolute command was split among the five satraps.
Source: Wikipedia