In the television series, the castle was owned by King Godred in the olden days. Now, the castle is part of the estate owned by Sir Robert Norramby. It has rails running through it, most of them dual-gauge, and its own station. There is a mine beneath the castle and it also has its own crane. Millie works and lives here, while she does a variety of jobs including helping the groundskeeper and taking tourists around the estate in an open-topped carriage. Stephen also works here as a tour guide as well as Glynn.
The castle has its own park area which is home to several deer including one that Luke once befriended. The park area is tended to by a groundskeeper who has his own lodge on the castle's grounds. It has dual-gauged railway lines via the Estate Railway.
- The drawbridge gained a barrier and signal in front of it in The Phantom Express.
- In the twentieth season, an engine shed was added at the castle.
- The Castle has its own turntable and crane.
- Concept art of the castle for King of the Railway shows that Ulfstead Castle would have been much larger than the final design, and the railway line would run through the main building. Tidmouth Bay would also be used as the railway station for the castle. Colin was also going to be based there.