Snowdonia slate trail is an 83-mile circular trail that explores the industrial heritage of Snowdonia. This trail can be covered in seven days or done in sections. As you walk through this trail, you will pass through all the major mountain ranges, lakes and rivers. If you are a railway enthusiast, you will definitely be thrilled to explore the Penrhyn Quarry Railway, Llanberis Lake Railway, Snowdon Mountain Railway, the Welsh Highland Light Railway and the Ffestiniog Railway.