And yes, the milestone says that Chennai is 5 km away. That actually means 5 km away from 'zero stone', which was near Fort St George, at Parry's Corner. (is the zero stone still standing? - must look that up sometime).
Wonder how much longer this business will go on; casuarina scaffolding is well on the way to joining the Madras Terrace and suchlike classics of yesteryear construction technology - we can see some of the latest being deployed whenever this lumber yard gives way to a new building.