The adventures of creating tourist traps. Niagara and the Mammoth Caves were big early ones because they were striking and unique; you couldn't get that in Europe. To be gloried in for their sublime and religious inspiration.
Not that that was always an advantage. Proper scenery was invested with stories and poetry. The Hudson and the Connecticut were big on the American Grand Tour because they were cultivated along most of their length, which is what proper scenery looked like. Washington Irving rewrote some German legends to create "The Legend of Sleepy Hollow" and "Rip Van Winkle," to intentionally invest the Catskills with the proper sorts of "charms of storied and poetical association." The scene of a disaster in the White Mountains, the Willey House, also provided some of the stories people expected.
Asylums and prisons were considered, briefly, a place to visit, until it became clear that the reformed institutions were not going to create new men out of their inmates. And the first people to move to the suburbs were the dead, with the new rural cemeteries -- which reflected a new attitude in religion, unlike the Calvinist terror of overconfidence, a hope in heaven -- which could be overconfident, and certainly allowed displays of luxury. They were great tourist attractions. Parks were first created in part to give people green places where they could have their recreation without doing it over graves. And handy to the city, which would no doubt morally improve its residents.
But Ruskins and others also changed the view of wilderness, which is one reason why Yosemite was saved as a national park. With much ado about its sublimity. (Though one man complained of a famous painter that he painted the mountains too skinny and tall -- they would blow over in a good breeze.) It was developed from the first as a tourist attraction.
As was Yellowstone, which tended to inspire more infernal than celestial thoughts, but others about the wonders of nature. Niagara got rather cleaned up, to prevent the clutter that had been allowed to encroach, and he discusses more touristy locations thereafter.