There are LDoN camps in Butcherblock Mtns, Everfrost, 2 in the new combined Desert of Ro (one north and one south)
<edit> oops, they didn't combine north and south they just got rid of oasis </edit> and one in the Commonlands tunnel.
Each camp has adventures in different themed dungeons, with the entrances to the dungeons elsewhere in the zone or sometimes in another zone completely.
This quest <
here> gets you an augment but more important it lets you use the Magus' that are in each camp to teleport from one camp to another. It also lets you use the Magus in the Guild Lobby to go right to any of the LDoN camps. You also need to stone to use a Magus to teleport to Nedaria's Landing to get to Abysmal Sea and Natimbi. You don't have to have the stone on you, once you get it you can keep it in the bank.
So .. to answer your question: do that quest then you can go to the magus in guild lobby and port right to any ldon camp whenever you want afterwards. You do not need the stone to do ldons, only to use the magus ports. Without the stone you will have to hoof it to an ldon camp. Easiest to get to on foot from PoK would be Butcherblock or Everfrost, the other 3 camps are in zones without PoK books going to them.
Ocean of Tears you can get to from a translocator on the docks in East Freeport or Butcherblock Mtns. I don't know if it's hard to get to the merchant there or not but invis should get you there okay I bet.
Edited, Aug 9th 2007 4:49pm by mfbrownbear