Gold & Silver Route 16
Celadon's western gate marks the head of the long downhill to Fuchsia.
Route 16 is in Kanto, with Celadon City to the east. In the story it comes after Fuchsia City and continues south to Route 17.
ROUTE 16 MAP
Pokemon Encounters
Slugma oozes across Route 16 at 5 percent, a Fire-type new to the region and the catch worth stopping for. Murkrow joins it once night falls, with Muk and Fearow holding the daytime.
Grimer
Also found in 3 other locations
Route 16 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.