Gold coin of King Rajabhata from the Khadga Dynasty in 670 CE

The Wari-Bateshwar region (Bengali: উয়ারী-বটেশ্বর Uari-Bôṭeshshor) in Narsingdi, Bangladesh is the site of an ancient fort city dating back to 450 BC during the era of Maurya dynasty. The 2500-year-old ruins being unearthed near the old course of the Brahmaputra River are a major archaeological discovery in south Asia. It challenges the earlier notions of early urban civilisation in Bengal.

• http://en.wikipedia.org/wiki/Wari-Bateshwar ruins