Stopping at the Weatherboard Inn in what is now Wentworth Falls, Darwin wrote:
"About a mile and a half from this place, there is a view exceedingly well worth visiting. By following down a little valley and its tiny rill of water, an immense gulf is unexpectedly seen through the trees. . .
"Walking on a few yards one stands on the brink of a vast precipice, and below is the grand bay or gulf (for I know not what other name to give it), thickly covered with forest.
"The point of view is situated as if at the head of a bay, the line of cliff diverging on each side, and showing headland beyond headland, as on a bold sea-coast."
According to Professor Nicholas "It's the first time he put these questions to paper, he's asking all these questions but he doesn't have any answers."
For example, after visiting Wentworth Falls Darwin speculated about how the valley was formed, initially believing it had been submerged and carved out by underwater sea currents.
Years later, as he developed his belief that the world had been slowly changing for billions of years, he suggested that the valleys had in fact been carved out by erosion over enormous periods of time.
And just west of the Mountains, Darwin saw creatures like the platypus and lion ant, and tentatively queried whether a creator could have come up with the design.