Gandhara, the country around Peshawar and Taxila, produced the first images of the Buddha in human form. Before Gandhara he was represented by a footprint, a wheel, an empty throne.
The style is Hellenistic in its drapery, its faces and its proportions, applied to Buddhist subjects, in grey schist. It is the direct result of Alexander's successors leaving Greek communities in Bactria and the frontier, and of Kushan patronage in the first and second centuries.
That image travelled. The Buddha as depicted in China, Korea and Japan descends from Gandhara, which means the standard image of the Buddha across east Asia was invented in what is now north-western Pakistan.
Kanishka, the Kushan emperor, ruled from Peshawar and his empire ran from central Asia into the Gangetic plain.
Sanghol in Punjab holds Kushan-period Mathura school sculpture, which is the other great school of the same period. Punjab sat between the two.
The sculpture is what it is known for: Buddhist subjects carved in schist in a manner that came out of the Hellenistic world, produced over several centuries in the Peshawar valley, Swat and Taxila.
The stupas at Takht-i-Bahi, Butkara and Dharmarajika are the standing remains. Much of the movable sculpture is in museums at Lahore, Peshawar and abroad.
Punjab is the eastern edge of it. Sanghol's finds, and the material from the sites along the Sutlej and the Beas, belong to the same Kushan period world and are almost never described that way.