In January 1933 a London Transport engineering draughtsman named Harry Beck redrew the Underground not as geography but as a circuit board: coloured lines running only at 0°, 45° and 90°, stations spaced evenly, interchanges marked by blobs and ticks. It threw away scale and kept only connection — and it worked so well it became the template for transit maps worldwide.

The system pairs that diagrammatic discipline with Edward Johnston's 1916 sans-serif and the red-ring, blue-bar roundel. The result is calm, exact, and unmistakably London: nothing decorative, every element load-bearing, every line legible at a glance on a pale pocket card.