The London Underground map, or Tube Map, was once actually many maps: like a number of early urban rail systems, the Underground began with separate lines run by different private operators. It wasn't until 1908 that the lines were consolidated onto one map. But the map remained a challenge to read until 1933, when Harry Beck's design traded geographic accuracy for a relative positioning of stations and their fare zone locations. Angles of route lines were locked at 45 and 90 degrees, helping legibility, and while topographical detail was left out, the Thames was included, lending the map a sense of connection to the grand city it served. Meanwhile, the map's unmistakable Johnston typeface and rounded logo, commissioned by former publicity manager Frank Pick, have become synonymous with London.
Remarkably, Beck was reportedly paid five guineas for his work, which he said was inspired by a similar mapping system for underground sewage systems. The map's basic design concepts -- mapping topologically rather than geographically, using different symbols to denote interchange stations -- remain in use in the current Tube Map and have been widely adopted for other train network maps around the world.