The Mountains. 
331 
underlying Coal Measures almost to sea level. The 
erosion of these gorges may be studied in many places. 
At Mulgoa the Nepean leaves the plain, and cuts its 
way for eight miles through a deep narrow chasm to 
Penrith, being joined in its course by the Warra- 
garnba, the last twenty miles of which lie in a rocky 
ravine, along which hardly a goat path can be found. 
The Burragorang and the Cox Rivers (united they 
form the Warragamba) How for many miles through 
valleys more or less wide, and of surpassing beauty 
and fruitfulness, though shut in by 1800 feet of sand- 
stone cliffs, to be climbed by a coach only at Burra- 
gorang, or by the horse pass at Wentworth Falls. 
From the Oaks, Picton, or Wentworth Falls, an 
enchanting district of flowing river, placid lake, and 
sentinel cl ills can be easily reached in one day. 
Accommodation 'may be obtained from the settlers. 
At the foot of the Wentworth Pass there are some 
limestones that have not yet been investigated and 
will repay examination. For bolder spirits the rarely 
trodden gulleys of the Kowmung River afford a 
fitting task. These valleys generally have a granite 
floor, and the surrounding cliffs give admirable 
sections of the Coal Measures, Narrabeen Shales, and 
1 lawkesbury Sandstones. 
The upper part of the Cox is easily reached 
from Katoomba through Nellie’s Glen. A visit to the 
coal and shale mine will be very interesting. A trip 
can be made along the path from the valley of the 
waters, under the cliffs lo the Wentworth Falls 
