Gilfach Ddu is now an intermediate station on the Llanberis Lake Railway, but it originally opened as the starting point of the Padarn Railway, the line which transported slate from the nearby Dinorwic Quarry down to Port Dinorwic (now Y Felinheli). The line closed with the demise of the slate industry, but this small section remained open as a heritage railway.
The modern heritage line was extended in the early 2000s to connect with the Snowdon Mountain Railway and Llanberis village, but train journeys still technically 'start' at this station - reversing down to Llanberis, before passing back through Gilfach Ddu and continuing on to Penllyn.
The cache should be something to do whilst waiting for the train. If you've just finished my Llyn Padarn series of caches and want to catch the train back to the top, make sure you ask for a single ticket to Penllyn and not the usual return (when I hid the caches, an adult single was £6.50)- the guard will need to open the gate for you at the far end!
About SideTracked Caches
This cache belongs to the SideTracked series. It is not designed to take you to a magical place with a breath taking view (well, maybe not usually ;) ). It's a distraction for the weary traveller, but anyone else can go and find it too. More Information can be found at the SideTracked Website