The Blue Mountains is the range of mountains in west of Sydney in New South Wales (NSW). It is well known for its steep cliffs, waterfalls, forests and its bush-walking trails. Katoomba, which is the major town in Blue Mountains, is accessible by public transport.
There are frequent trains that run between Sydney CBD (Central train station) and Blue Mountains. Katoomba is the main train station of Blue Mountains. But hikes/walks can start from different towns within the Blue Mountains. More and updated information on the public transport in NSW can be found on NSW Transport website.
Opal Card is the card used to travel on any public transport. And they can be bought and topped up at any train station or news agency or 7/11 stores or online. More information on where all Opal card can be used is found on the Opal website.