The primary Greek column entered the Khyber Pass, but a smaller force under the personal command of Alexander went through the northern route, taking the fortress of Aornos (modern-day Pir-Sar) along the way—a place of mythological significance to the Greeks as, according to legend, Herakles had failed to occupy it when he campaigned in India. Here, the Hindu clans of Hindu Kush gave Alexander's army the toughest opposition they had faced, but Alexander still emerged victorious, despite being outnumbered, depending on the source, somewhere between 3:1 and 5:1.