Trainspotters in the United Kingdom
A trainspotter, also known as a locospotter or gricer, is a member of a British subculture that was popularised in the 1940s. Based on the spotting of locomotives and recording of their numbers, the subculture gained a notorious reputation in British popular culture during the twentieth century.
Source: Wikipedia — Trainspotters in the United Kingdom (CC BY-SA 4.0)