Tidmouth Tunnel

Tidmouth Tunnel, also known as the Castle Tunnel, is a tunnel on on Duck's Branch Line between Tidmouth and Tidmouth Hault.

It first appeared in the third season and made numerous appearances until the ninth. The architectural style changed in the later seasons. Although never mentioned by name in an episode, it was first named in an eighth season learning segment. It returned in Tale of the Brave in the same architectural style as the third season. It also appeared in The Adventure Begins.

In the television series, this is where James once tried smoking bees off his boiler.

Trivia

 * The lake next to the tunnel shrank in the later seasons, gradually being replaced with hills, until it was no longer visible. It became visible again in Tale of the Brave when it returned in CGI.
 * The number of tracks leading through the tunnel changes several times: most of the time there are two tracks, but there have been occasionally one to three.