An hour west of Sydney, Penrith is the door to the Blue Mountains. This plateau area blocked the progression of the explorers towards the inside of the continent before they discovered that they should cross it on top of the plateaus instead of at the bottom of the valleys.
The valleys and plateaus are covered with a blanket of Gum trees (eucalypts), which colour and emanations give a blue haze to the panoramas.
One of the rock formations is famous, called the Three sisters. You arrive from Katoomba on the top of the plateau, and can start descending a very impressive (and thigh-pain inducing) steep staircase along and under the three columns.
Once you’re down in the valley, you have won a pleasant trip among the trees, some taking weird shapes, and you can hear the cascades long before you see them. A 45degrees inclined railtrack can take you back up… or you can walk.