Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Mammoth Cave National Park' has mentioned 'The Bottom' in the following places:
Occurrence Sentence Text Source
For example, the large Main Cave passage seen on the Historic Tour is located at the bottom of the Girkin and the top of the Ste.
In the spring of 1838, the cave was sold by the Gratz brothers to Franklin Gorin, who intended to operate Mammoth Cave purely as a tourist attraction, the bottom long having since fallen out of the saltpeter market.
He was the first person who ever crossed the Bottomless Pit, and he, myself and another person whose name I have forgotten were the only persons ever at the bottom of Gorin's Dome to my knowledge."