Railway station in Travelcard Zone 2 opened 1863.
The busiest station in the UK.
One branch of the London Overground terminates at Clapham Junction.
See also Clapham High Street Station, Clapham Common Station, Clapham North Station and Clapham South Station.
More information on the Wikipedia page [1]. The TfL page is [2]. There are various videos, including [3].