Both were key hubs and cultural melting pots on opposite corners of the Silk Road.
From the Guardian article about Mes Aynak:
...Its mountains and valleys were a major intellectual crossroads where the Hellenistic, Persian, Central Asian, Tibetan, Indian and Chinese worlds met and fused. Today, of course, part of what is so fascinating about the civilisation of the cities of the Silk Route is the sheer remoteness of these exotic-sounding places. Yet what most distinguished Mes Aynak in the early first millennium AD was the opposite: the fabulously wealthy and cosmopolitan nature of the society that thrived there.
At this period, Afghanistan was the epicentre of classical globalisation: midway on the trade route from Rome to China, traders came to Afghanistan from all over the world, bringing painted glass from Antioch, inlaid gold vessels from Byzantium, porphyry from Upper Egypt, ivories from South India, carpets from Persia, horses from Mongolia and Siberia, and lacquers and silk from the China coast. It was through these now-remote valleys that ideas of art, decorum, dress, religion and court culture passed backwards and forwards, east to west and back again, mixing and melding to create the most unexpected conjuctions. The slowly decaying remains of the culture that emerged from this extraordinary clash and fusion of civilisations still litters much of Afghanistan and northern Pakistan.