Hidden Hollow Locations in Black 2 / White 2
~edit: I've found the ones Serebii has listed except for route 12. I'll update if I find more. Thanks to Too Funk to Druck and Dark Ray for showing me new locations.
~edit2: I received the medal: Hidden Hole Expert 'Find all the Hidden Hollows' so this is the full list. Happy hunting!
route 2 (post-game)
- Enter route from Accumula Town. Head north. It's right above a female Veteran and to the left of this Lass.
route 3 (post-game)
- Enter route from Striaton. Go left past the daycare. Go down, go past the female cheerleaders, and go to the tall grass to the right.
route 3 (post-game)
- Enter route from Nacrene. Head right and on the bridge, use Surf to get to the top of the pond.
- Enter route from Nimbasa. Head northeast. Bianca showed you this one.
- Enter route from Driftveil. Go directly above the female Pokemon Breeder.
- Enter Route 6 from Driftveil. Make your way to Chargestone Cave entrance. Head southeast into the tall grass and surf to the right. The hidden hollow is right in front of Mistralton Cave.
- Enter route from Mistralton. Use the raised walkway to go straight to the hidden hollow.
- Enter route from Opelucid. Head west, and past the shopping mall building, you'll find the hidden hollow tucked away in a corner.
- Enter route from Lacunosa. Go right and go through the boulder requiring Strength. The hidden hollow is near some stairs that lead you down to a small area of water.
- Enter route from Lacunosa. Head south, either taking the Cut shortcut or going through the grass (has female Pokemon Ranger). The hidden hollow is then to the left.
route 18 (post-game)
- Enter route via surfing from Route 17. Make your way to the house (where a female Ace Trainer heals your Pokemon). Go west and down the stairs, you'll see the hidden hollow.
- Enter route from Shizui's town (8th gym). Go to where you found Terrakion in the middle. Go down, then head towards the female Ace Trainer in the southwestern area. Head north using the raised walkway with the S patterns. Take another raised walkway leading you to the hidden hollow.
- Enter route from Victory Road gates (where you checked your badges). Head southeast and take the bridge heading south. After that first bridge, go right. From the male fighting-type trainer, go down. Continue on this westward path then and you will find the hidden hollow near the end.
- Enter ranch. Head northward into the grassier area (the area you fought a Plasma grunt). Surf right.
- Enter route from Giant Chasm cave. Go straight up and you'll find the hidden hollow in the first grass patch you touch.
- Enter area. It's northeast, near a Youngster.
- Enter area. Make your way to the shrine in the north. Go right and use Surf.
- Enter forest. Go to the northernmost wall. The hidden hollow is above the male Pokemon Ranger.
pinwheel forest (post-game)
- Enter route from Skyarrow Bridge. Head south and enter the gap in the white fence on the right. Make your way to the river and surf left.
pinwheel forest exterior (post-game)
- Enter area outside the forest. Go down and past the train tracks. Start heading to the right past a female Ace Trainer and go up some stairs. Head northeast towards the Challenge Rock to find this hidden hollow.