New underground station?

An Irish friend asked for the way in the London Underground and was told that she had to change trains in a place called Olden or Owden or something like this. She did not quite get the name but was sure it began with an O. So she started for the underground map and looked for such a station but could not find any. No station of the London Underground seemed to begin with an O. So she went back to the information desk and asked again. The man emphatically repeated the name of the station, pointing at the same time at the name of the place on the map. It was Holden.