Railway station in Travelcard Zone 3 opened 1871 as "Castle Hill and Ealing Dene" on the Great Western Railway.
From 1 March 1883, the station (then named Castle Hill (Ealing Dean)) was served by District Railway services running between Mansion House and Windsor. The service was discontinued as uneconomic after 30 September 1885.
Only platforms 3 and 4 remain, platforms 1 and 2 having been removed in 1973 and 1991 respectively.
The station was located next to the London Co-operative Societies main creamery, and so was equipped with a dedicated milk train platform.
More details, including the possibility of Crossrail services, on the Wikipedia page .