The marching troops at the Amphitheatre against the backdrop of the Old Fort (Purana Qila) or Rajendra Prasad taking a ceremonial ride at the Great Place (now Vijay Chowk) without any security cover, stand today as signatures of that momentous day in Indian history before the venue shifted to the Rajpath the next year onwards.
Incidentally, Lord Irwin was the then Viceroy of India when New Delhi was formally inaugurated in February 1931, as the new capital of the British India in a grand ceremony. But, it wasn't just the Capital celebrating the red-letter day.