Gold & Silver Route 18
Near Fuchsia, that long downhill finally levels out and ends.
Route 18 is in Kanto, with Fuchsia City to the east. In the story you arrive from Route 17 to the north and it comes before Route 15.
ROUTE 18 MAP
Pokemon Encounters
More Slugma and Muk crawl the east end of the Cycling Road, Fearow circling above and Corsola biting the rods down at the water.
Grimer
Also found in 3 other locations
TRAINERS
2 trainer battles at Route 18. Team rosters, levels, and weakness coverage for each.
Bob
Route 18 Guide
Yes, and it's new to the series. Gold and Silver run on a real clock split into morning, day, and night, and the grass swaps species along with it. Hoothoot only turns up after dark, for instance, where the daytime route hands you Pidgey. If something won't appear, come back at a different hour.
Material for custom Poke Balls. Routes 37 and 42 and Azalea Town have trees that each drop one Apricorn a day, and Kurt in Azalea turns a color into a matching ball by the next morning. A white one becomes a Fast Ball for skittish Pokemon, a black one a Heavy Ball for heavy catches like Snorlax.