It really makes you believe that old is gold when a Mumbai building adopts the water harvesting system that was used by the Harappan settlement in Dholavira in Gujarat some 5,000 years ago. The Chhatrapati Shivaji Maharaj Vastu Sangrahalaya, formerly Prince of Wales Museum, became the first heritage structure in Mumbai to adopt rainwater harvesting recently. And, the inspiration came from Dholavira which excelled in water harvesting technology with dams, drains, reservoirs and storm water management that eloquently speak of the engineering skills of builders of that era.