Wayward Cave - Pokemon Diamond, Pearl and Platinum Wiki Guide - IGN
Since we talking about Sinnoh, did you know Route 206 was Hitomi Sato's very first piece of music for Game Freak? And it became one of the best Pokémon route themes ever. :
Route 206 at 100% in Brilliant Diamond and Shimmering Pearl: Pokémon and secrets - Code List
Sinnoh Route 206 | Pokémon Wiki | Fandom
December « 2012 « Pokemon Diamond Gameplay Journal
Route 206 | Game of Guides
Sinnoh Route 206 - Bulbapedia, the community-driven Pokémon encyclopedia