i do not know but you can go on ask.com
lugia is on the top right island
the top one on the right
I believe the Top Right island.
the one in the left top
lugia is in the whirl island on the top right cave
In Pokemon Heartgold, Lugia can be found at the top-right island of the Whirl Islands Area. It's at Lv. 70 so prepare.
To find Lugia enter the Whirl Island Caves at the top-right island, then it should be pretty easy from there (if you're stuck use youtube or similar.)
get the silver wing from an old man in pewter city,go to whirl island,top right
Which island? whirl islands? Cinnabar island? you catch lugia in whirl islands. you beat blaine in cinnabar island.
all of the island
On whirl island
use the island to the top right and inside go straight up and go down the ladder