Nathnagar, on the western edge of Bhagalpur, is the heart of the city's silk-weaving industry. The neighbourhood's streets are lined with small workshops where handlooms clack through the day, producing the distinctive Bhagalpuri Tussar silk — officially known as Bhagalpuri silk or Bhagalpuri fabric and recognised with a Geographical Indication tag.
Wandering through the lanes, you can watch the whole process: weavers sitting at pit looms, the clatter of flying shuttles, lengths of silk being inspected by morning light before sale. Most workshops are family operations with no formal visiting hours — walk in respectfully and most weavers are happy to show you what they're doing and sell fabric directly. Prices are significantly lower than in city shops. Look for the natural undyed Tussar in warm gold tones, or the hand-block printed versions dyed with local vegetable dyes.
The central market in Bhagalpur also has fixed-price silk shops if you prefer a more structured buying experience, but the Nathnagar workshops are more interesting.