There are several entrances into Quicksand caves in both Western and Eastern Altepa, so it really depends on which entrance you need. To access the area for the first time is done through Eastern Altepa through the Korroloka Tunnel via Bastok. If you have the Teleport-Altepa Crystal you can teleport in via that means. You can also use the HomePoint Crystal in Rabao which exits into Western Altepa. There is also the Outpost Warp if you have that Outpost in Western Altepa.
Now that I've covered all the ways that you can get to Eastern and Western Altepa (the map below will show you where to zone between the two areas).....now you have to look at the TWO Altepa maps and figure out which entrance you want. And I wish you major luck on that. Every time my hubby says we have to go to Quicksands for a mission or quest I just whimper because I know the next several hours will be filled with me following him thru entrance zones and tunnels that all look a like, getting aggro even at 99 (I'm his Elvaan hit squad)...and he knows exactly where he is going, but I have no clue. I've been playing since 2007 and I've only memorized 1 area and that was because it was a party area back in the day.
Here are some links below that should help. The page has general zone coordinates and the maps can be enlarged showing all the different entrances for Quicksand Caves. HAVE FUN!! Skyfiredancer (talk) 22:34, November 26, 2015 (UTC)