KnowraLondon UndergroundLinked fromLinked fromThe 12 pages that link to London Underground, each with the reason it gives.All 12Broader topic 2Related 3Narrower topic 1Compared with 6Urban rail transitBroader topic: It is an early and influential example of urban underground rail.History of LondonBroader topic: Its expansion changed how Londoners moved across an increasingly vast city.