Osama Bin Laden was just down the road from Karakul Lake

Karakoram Highway map

Karakul Lake is north of Tashkurgan, next to Muztagh Ata.  So just take the highway south, cross the border into Pakistan, and stop at Abbottabad.  If you see the AMC Theatre Hall in town, you've gone too far.

Muztagh Ata is the mountain in the background.  Karakul Lake is in the foreground.

My Karakoram Highway trip:
Part 1
Part 2