Actually getting to Beaucedine [S] is pretty simple, but there are a few things that you have to do in advance the first time you make the trek. You will need access to the Wings of the Goddess expansion, but since you are asking for direction to Beaucedine [S], it's a pretty safe bet you already have that expansion. You will be entering thru Batallia Downs [S] - I know sounds strange, but bear with me.
First you will need to make a stop and buy a stack of flower. I will paste a link below regarding the types of flowers you will need and the ones that will NOT be needed. There will be a Lycopodium NPC in Batallia Downs [S] that you will be trading a flower too. There are 2 other places, North Gustaberg and Garlaige Citadel that there Lycopodium NPCs are stationed to provide "short cuts" - so it might be a good idea to get into a habit of carrying a stack of flowers with you.
You can pick up a stack of flowers at the M & P shop in Upper Jeuno at G-6. They are a Standard Vendor so you shouldn't have any problems getting the flowers that you need.
Now hopefully you already have access to the Cavernous Maw in Batallia Downs that is located at H-5. If you don't, this might be a good time to swing by it to add it to your list of Maws on your way to Beaucedine [S]. If you do have the Cavernous Maw at Batallia Downs, simply go thru the Maw into the Past and head for the Lycopodium NPC at F-5. You will trade a flower to the Lycopodium and get a cut scene. After the cut scene you will be transported to the ledge above you.
If you do not have the Batallia Downs Maw, here is a list of Maws so you can plot a course to get to this one. Remember you have to travel to all new Maws in the PAST in order to "activate" it.
In the future when you reach that spot in the Past or the Present there will not be a Lycopodium NPC, just a sparkly patch on the ground that you will trade a flower to - that will trigger a cut scene - that will transport you to the ledge above or below you.
Once you have been transported to the ledge, head straight north to F-5 to the ramparts/doors that will lead to a cave like entrance where you will zone into Beaucedine [S] at E-4. You can also use this entrance in the Present. You will come out at the bottom, left hand side of the map, approximately H-12. Skyfiredancer (talk) 06:07, August 6, 2015 (UTC)