(GMT)04 FEB 2017 J2AS:
Here is Piccadilly Circus cutaway, London Transport Museum, 1989. Illustration by Gavin Dunn.
Cutaway or cross-section drawings are mostly just fancy residues of a long-gone era when engineering and architecture visualisation was based on hand-drawn images that were often closer to art than boring illustration.
Piccadilly Circus is well known for its crowds, Eros Statue and wall of illuminated advertisements in the northwest corner, one of very popular tourist attractions in London. But it is actually just a busy(maybe the busiest) road junction. The best thing about this junction is that the steps provides a place to relax although it is very noisy place.