The Khyber Pass is the pass that connects Pakistan with Afghanistan. The Khyber Pass is about 33 miles (53 km) long, traveling through the mountain range of the Hindu Kush. The pass reaches a maximum elevation of roughly 3,500 feet (1050 m), just at the border between Afghanistan and Pakistan.

Once in the pass, it is incredibly difficult to climb the mountains to either side. In some rare places the faces become climbable, but generally are sheer cliffs ranging from 575 feet (175 m) to 1000 feet (300 m). At its widest point the pass is about 450 feet (135 m) across, and at its thinnest it is a mere 10 feet (3 m) wide. Despite this, two highways currently go through the pass connecting Peshawar with Kabul. One highway is used for traditional caravan traffic, while a second is used for modern motorized vehicles.

The Khyber Pass is inhabited by the Pathans, a group of Pushtu-speaking tribes. Pakistan nominally controls the Khyber Pass, but in reality it is administered by the Pathans. The Pathans are very traditional, and are known to be very fierce fighters. Large numbers of the Taliban fighters of Afghanistan came from the Khyber Pass region, and this is thought to be one of the most likely locations of Osama bin Laden.

The Khyber Pass is arguably the most important pass in history, with countless invasions and migrations using it to traverse the Hindu Kush. Some historians believe that the Khyber Pass was used by the Indo-Aryans on their way to India around 1500 BCE. This would make them the first major invasion of the Indian subcontinent to have used the pass.

Later, in the 6th century BCE, Darius the Great led his Persians through the Khyber Pass to expand the Archaemenian Empire into India. Two centuries later, Alexander the Great followed in Darius’ footsteps leading his own army to India through the pass, but only after bribing local Pathan chiefs to allow him free passage. The Huns, the Scythians, the Afghans, all used the pass during their various conquests.

In the 10th century Islam made its way to India through the Khyber Pass. Subuktagin began his invasion of parts of India through the Khyber Pass, and his son later used the pass nearly twenty times in his own campaigns. In the 16th century Zahirurddin Babur led his army through the Khyber Pass, using it to establish the mighty Mughal Empire in India, cementing Islam’s place as a major religion on the sub-continent.

When the British seized India, they watched the Khyber Pass with great concern. It was through the Khyber Pass that they feared a Russian invasion, and for many years the British attempted to seize control of the pass from the Pathans. During the First Afghan War the British suffered massive losses against the Pathans, before eventually recruiting the tribes to fight British army.

The Khyber Pass is, without a doubt, one of the more exciting and dangerous 33 miles on earth. Since the 1980s the region has been the site of combat between the Pathans and various factions, from the Russians to the Americans to the Afghans. Smugglers use the pass extensively, and the summit town of Landi Kotal is known as a center of both hashish and black-market weapons. Travel through the pass by visitors is available only with an armed guard, and even then is a rather risky affair.