One of the unique features that made the Concorde able to cruise at twice the speed of sound was its ability to change the shape of its forward fuselage. For ground handling, take-off and landing, the nose could be lowered and a near-vertical windscreen gave the pilots excellent visibility. But once in the air, the nose would be raised, and a steeply sloped screen would rise to provide-near-perfect streamlining.

That's all easy enough to describe, but it's a spectacular sight when you actually see it happening. 

Concorde's nose-lowering demonstrations take place on the last Sunday of every month.