This is one of the memories that can be triggered after obtaining the Ashen Mist Heart from the Ancient Dragon. To trigger the memory return to the cave where you fought the Duke's Dear Freja in Brightstone Cove Tseldora. Approach the formation in the ground directly below the dragon's head. Choosing to examine it transports you to the Dragon Memories.
The Dragon Memories is a very brief memory event. The ashen landscape is barren except for an ancient Dragon at the far end, who lies deceased. Approach the dragon and examine to receive the Ancient Dragon Soul. Examining it once more transports you back to the cave in Brightstone Cove Tseldora.
- It's a bit curious that the Ancient Dragon Soul has the inscription: "Soul of the great ancient dragon that stands magnificently, deep within the shrine. This powerful being stands and waits, for whoever may visit him." But upon reaching him he is lying down, long dead and petrified, so it has probably been a while since he had any visitors.(Note: This could possibly be the ancient dragon in the first Dark Souls that was in Ash Lake, as the description of the soul is reminiscent of what the original dragon did.)
- It is possible that the souls inscription is actually referring to the to Ancient Dragon in the Dragon Shrine. The soul says "Use the dragon soul, created by those who peered into the essence of the soul". This could indicate that the Ancient Dragon in the Dragon Shrine was created by King Vendrick, this would also mean that the Ancient Dragon in the Memory was also created by someone and is not one of the original dragons.
- The description of the Lingering Dragoncrest Ring, compared to that of the one in the original Dark Souls, suggests that Dark Souls 2 takes place in what was once Vinheim. (Seeing as how there was a lingering dragoncrest ring in Lordran and that the only evidence that supports Drangliec as being Vinheim is the assumption made from the ring description, this theory is a complete leap of faith. It is much more likely that Drangliec is located on what was once Lordran.) <-(Youre right for speculating this, you just needed to present the facts friend.) (The game is pretty explicit that Drangleic isn't Anor Lando. (nearly?) all of the hold-over armor sets from the first game such as the Darkwraith armor explicitly mentions that Anor Lando is a foreign land to Drangleic)
- Not so much of a leap friend, considering that the Lingering Dragoncrest ring in dark souls 1 said it was used by Vinheim mages... Dark Souls 2 version of the ring says "used in a land where Drangleic is now", logic would only tell you that this means Vinheim's land is now Drangleic's land, It may seem there is also a ton of evidence suggesting Drangleic is in fact Lordran but just hundreds of years into the game's future. Maybe(in the attempt to allow all opinions and theories to co-exist), all the lands that are mentioned in souls games were all part of one huge "Pangaeic" land in the primordial ages thousands of years ago, only SIMILAR to the land you visit entering an ancient dragon's memory in the room where Dukes Dear Freja is encountered. That primordial land might be showing the AFTERMATH of the Demon/Dark Soul's version of a unified land, "Pangaea".(credits to this Pangaea theory to XboxGT; Alexxx8th)
(Work in progress!)