Just out of the capital, Islamabad, past its twin city of Rawalpindi, lies one of Pakistan's ancient treasures: Taxila or Takshasila, built by the Achaemenians in 6th century BC. It is one of the regions most rich archaeological sites, though sadly much was destroyed by religious fanatics. Taxila was one of Gandhara's most important cities (Gandhara is the old name for the Peshawar Plain), visited by Alexander the Great, where Mauryan emperor Ashoka built a university. Bactruan Greeks and Kushans both extended this city where it was a centre of culture in a large Central Asian empire until the White Huns destroyed it in the 5th century.
Bhir Mound is often the first place visited, near the museum, which was the Gandharan center, and bears a resemblance to similar Buddhist mounds on the other side of the Indian subcontinent. Streets, shops and steps have been neatly excavated. At the other end of the complex is Jandial, which is of Greek style, including ionic columns.
Jaulian and Mohra Moradu are complexes further away from the main center, but house the fascinating monk cells of a monastery and the amazing collection of bas relief Buddhas, elephants, and other creatures.Source: Lonely Planet Pakistan & The Karakoram Highway, 7th Edition