text: kal main ek documentary dekh rahi thi,usme indus valley civilization ke baare mein bataya gaya tha, kitna advanced society tha woh log, samajh nahi aata ki kaise itna kho gaya.bilkul, woh log toh plumbing aur drainage system mein bhi aage the, aaj bhi unki architecture ki tareef hoti hai, par hum aaj bhi unki history ko explore nahi kar rahe.