English: The diamond Crossing at Nagpur is a unique marvel of engineering that exists in very few places in the World. Nagpur is where trunk railway lines running from Kolkata in the Eastern end of India to Mumbai in the Western end, and the one from Delhi in the Northern end to Chennai and other places in the southern end cross. Nagpur in fact is the geographical Centre of the Indian subcontinent. The double lines crossing from the North to the South and those from East to West form a square shape and is called the diamond crossing. It is crucial and is used widely. The people who operate the lines are ever vigilant. Narayan Ramdas Iyer at the Diamond Crossing, Nagpur.