Taxila, in Pakistan's Punjab province's Rawalpindi district, is a sprawling serial site that contains a Mesolithic cave and the archaeological ruins of 4 early village sites, Buddhist monasteries, and a Muslim mosque and schools. Taxila flourished during the 1st and 5th centuries, ideally located on a branch of the Silk Road that connected China to the West. The archaeological sites of Saraikala, Bhir, Sirkap, and Sirsukh are unique in their ability to depict the emergence of urban settlements on the Indian subcontinent. The Bhir mound is Taxila's oldest historic city, and it was most likely founded by the Achaemenians in the 6th century BC. Another notable visitor was the 1st century BC neo-Pythagorean sage Apollonius of Tyana, whose biographer, Philostratus, described Taxila as a fortified city laid out on a symmetrical layout and compared it in scale to Nineveh, an old Assyrian city. In 1980, Taxila has designated a UNESCO World Heritage site.