Search along the aquity lake front until you find a wall that you can use rockclimb on.Scale it(obviously with rockclimb)and there is the entrance pretty much straight ahead!Hope this helps!
You will have to go to Routes 216 and 217 and in the Acuity Lakefront, Lake Acuity and in the 5 floors of Snowpoint Temple in order to locate a wild Sneasel at which point you will be able to battle it in an attempt to catch it.
go in the lake enterance and he or she should be there.
go to route 217, acuity lakefront, lake acuity (walk in the grass and it will appear only at night and at these exact places) it's encounter is random and it is not rare because i encountered 87 in a row
go out of the area with team galactic are standing some where (my brother done it for me)
you could cheat but that sucks so here is how to do it.1. get Pokemon platinum 2. get Pokemon emerald 3. insert them into the right slots 4. start playing platinum and go to Route 211 (West), Lake Acuity or Route 216, Route 217, Acuity Lakefront and you will find a ursaring or Teddiursa hope it helped (p.s it might take some time)
go to snowpoint city and go to the sailor. Dont talk to him. Go left to some stairs and it will get you to acuity lakefront. But to get to the lake, you'd have to go north until you can see a place that you can use rock climb. Use it. Go left until yo see a break in a tree. Go into that break and you will enter lake acuity
Use a Pokemon to Fly to Acuity Lakefront from Celestic Town. If you don't want to Fly whatsoever, then go west into the tallest mountain, and then going north all the way, then past the whole snow and blizzard.
you go to snowpoint city and you walk through and battle all of the trainers then you walk up to the top and there will be a place were you use strength and you go up there and there is acuity lakefront
Go to the place where you can walk with your Pokemon and it's in one of the places. Town: Hearthome You can also get it at the Acuity Lakefront, Route 229, and at Turnback Cave
master ball event
go to acuity lakefront and talk to your friend
If you're walking on Route 217 and you go in the north direction you'll enter Acuity Lakefront. Then you're going north again and you'll enter Lake Acuity.