Bertram's Old Mine (also known as The Old Mine) was owned by Sodor Gold Company until the company and mine closed. Duke, Stuart and Falcon formerly worked here, when the mine was served by the Mid Sodor Railway.
At some point, Bertram was abandoned there and nature overgrew the mine and all the leftover scrap. Toby discovered the mine when he took Sir Topham Hatt and his grandchildren exploring. Whilst on guard one night, Toby found Bertram, now they, Skarloey and Rheneas take visitors to and from the attractions that have been built on the site. There is also a Skarloey Railway station at the mine.
- The station building looks similar to the Lower Tidmouth and Norramby Church Station buildings.
- On the 2014 television series map, the mine is said to be located near Ffarquhar Road and Tidmouth Bay, however there are no Skarloey Railway narrow gauge tracks leading here.