Prince of Persia: The Forgotten Sands

There are 21 sarcophagus locations in the game that are required for this achievement. This youtube video is pretty good. I take no credit for the video, just found it and shared it.

I have recieved permission from the author of the above article(CrustyDirtDemon) to post his complete walkthrough on this site so people don't have to be redirected.

Prince of Persia: The Forgotten Sands

Collectable Guide

There are 21 Sarcophagus collectables in PoP:TFS, all of which can be obtained in one play through. Each and every one of the sarcophagi emits small blue orbs if you are close enough and makes a distinguishable sound. SO PAY ATTENTION. If you happen to die after smashing a sarcophagus go back and check that it’s still destroyed, just to be safe. ALSO BE VERY AWARE that you can not REPLAY any sections of this game. AND for the most part upon entering a new area a door will close shut behind you making it IMPOSSIBLE to back track, and if you missed a collectable you will have no choice but to start a new game, or wait until you finish your current play through and go back to get the one you may have missed on a new game. I have labeled the LOCATION of each sarcophagus to make it easier for you to be AWARE of when a collectable is coming up or near by.

-The very first sarcophagus will be pointed out for you right before exiting the stables. Simply climb up the rocks then jump to the wooden beam behind you, the jump and wall run up to the sarcophagus.

-Location: The Fortress Courtyard. Impossible to miss, as this collectable is directly underneath a pressure plate that you must activate to continue on.

-Location: The Fortress Courtyard. Shortly after the last collectable you will come to and outdoor walkway. This walkway has spikes that come out of the floor and wooden spikes rotating around the spiked floors. You should see the collectable and the bottom left of your screen before proceeding into the first small area with enemies. Kill or ignore these enemies and pass one set of spike floors and then drop off the ledge. Drop down to a grab point and make your way to the right. Pull yourself up at the end and smash the sarcophagus.

-Location: The prison. Before finally exiting the prison you will use a pressure switch to raise a gate. Run past the spiked floors and shooting arrows and roll under the closing door. BEFORE exiting look to your right for the stone slabs on the wall that you can climb. Climb up and proceed to your right to snag this sarcophagus.

-Location: The Sewer. Shortly after entering the sewer you will find your self climbing up a frozen water spout. From here you jump onto a wooden beam. NOW from here you may notice that there is another beam slightly higher than the one you are currently standing one. From the first wooden beam jump and grab the frozen water spout. Shimmy up this spout and jump off it to the beam above the first beam. From here simply jump the gap and break the sarcophagus.

-Location: The Sewer. Before exiting the sewer take the side path that leads left. Use your water freezing ability to swing from on spot to the next and smash the sarcophagus.

-Location: The Royal Chambers. You will eventually enter a room that has a water spout to the left hand side of the room. To the left and right of this spout is a pressure switch. Freeze this water spout, climb up and jump off the spout and hit the switch. Rinse and repeat on the opposite switch and a secret door revealing the sarcophagus will be opened.

-Location: The Royal Chambers. Midway through this area, you will come to a section of frozen water jumps. There will be a waterfall to your right and left, along with two spouts in-between these waterfalls. Make your way up to the second spout and swing to your right. Jump off the spout you’re swinging on and in mid air let go of the LEFT TRIGGER to un-freeze the water. You will pass through the waterfall and pull yourself up on a ledge that hides this sarcophagus.

-Location: The Royal Chambers. Near the exit to this area you will come to a room with a water wheel. Directly to the right of this wheel is a ledge you would normally grab to continue on. Instead of freezing the water which stops the wheel, WALL RUN up from this ledge and grab the rocks on the wall. Jump off the wall to the pole, and jump from the pole to the ledge on the wall. Shimmy left and you will reach the sarcophagus.

-Location: The Throne Room. As soon as you enter this are look to your left and you will see the climbable rocks. Climb up them and proceed to the balcony to claim your sarcophagus.

-Location: The Terrace. You will come to a section where you have to slide down multiple banners to reach the bottom. On the way down you will see the sarcophagus. Once you reach the lower level with the enemies either kill or ignore them and wall run up to the ledge on your right. Wall run up some more and smash that sarcophagus.

-Location: The Rooftop Gardens. Shortly after entering this area you will reach a cut scene showing your brother fighting of enemies. Make your way towards where he just was and look behind the palm tree to find the sarcophagus.

-Location: The Rooftop Gardens. Eventually you will find your self on a large octagon shaped platform fighting off loads of enemies. Kill these enemies and DO NOT use the power of flight to reach the enemy across the gap. INSTEAD look to your left at the waterfall. Jump through it and climb up the wall to reach the sarcophagus.

-Location: The Aqueducts. After fighting a bunch of enemies on a semi-circle platform, some vultures will appear. DO NOT jump to these vultures yet. INSTEAD go to the left hand side of this platform (left if you’re looking at the vultures) and jump down and in mid air freeze the water spout. Make your way around these spouts until you see the sarcophagus hiding behind a waterfall. Drop off from the frozen spout and claim what’s yours.

-Location: The Ruins of Rekem. Upon making your way through this area you will jump off a frozen water spout onto a wooden beam. From here you can either go left or right. BUT WE WANT TO GO LEFT. Use the LEFT BUMPER to make the platform on your left appear. Jump to it, and proceed into the alcove to smash your sarcophagus.

-Location: The Ruins of Rekem. After leaving the area VERY shortly after the last sarcophagus, you will slide down a banner to solid ground. In front of you are a door, and to your left is a railing and a waterfall below it. Hop over the railing and go through the waterfall to find this not so well hidden sarcophagus.

-Location: Rekem’s Throne Room. Upon entering this area you will get a cut scene that shows the stone THRONE. You will most likely see the sarcophagus through the semi-see through wall (the ones you use LB to make solid). Approach the throne and turn left. Climb the rocky wall and proceed straight. At the last pole you’re swinging form jump off and grab the ledge against the wall. Shimmy left and use LEFT BUMPER then solidify the wall. Wall run to your left and drop down. From here wall run up and grab the first ledge, wall run up once more to grab the higher ledge. Shimmy left and wall run and jump over to the opposite ledge. Shimmy right and drop down to the ledge below. Use LEFT BUMPER to solidify the platform below you, and then drop down. Once on the solid platform walk to the middle of it and use LEFT BUMPER again but this time to UN-solidify it and fall through thus reaching your sarcophagus.

-Location: The Rekem Reservoir. After killing the “Titan” that comes out of the ground and all other enemies in the area, proceed over to the waterfall on the left. Jump through it and over the gap. From this small alcove roll under the small gap to find a well hidden sarcophagus.

-Location: The Rekem Reservoir. Shortly after the previous sarcophagus you will reach a platform with a STONE LION FOUNTAIN. Drop off the left side of this ledge and drop down the rocks below. Climb down these rocks and then wall run left to grab a ledge. Shimmy to the left on this ledge and you will find probably the most well hidden sarcophagus in the game. WOOT WOOT…

-Location: Solomon’s Vault. You will enter a room with a giant STATUE of KING SOLAMON. And you will get a cut scene where the girl “Razia” tells you that you need to make him face the door. BUT before we do this find the pressure switch on the wall. To get here you will need to wall run from the bottom floor and jump opposite to a poll, swing from this pole to the next pole and jump off to the ledge. From here shimmy right, and then wall run thus activating the pressure switch. IMMEDIATELY after activating the pressure switch jump off and get your self under the closing gate as quickly as you can. (this may take a few attempts to get your timing down) Inside the gated area will be your second to last sarcophagus.

-Location: The King’s Tower. Upon making your way up this tower you will use the power of flight to travel using a bunch of VULTURES. Upon reaching the last vulture you will need to in mid air use the LEFT BUMPER to solidify the ground. DO NOT PROCEED UP FROM THIS LEDGE. INSTEAD look to your right for another set of VULTURES that you can jump to. Follow this string of vultures to the top of the area and claim your last sarcophagus.

DING ACHIEVEMENT UNLOCKED “GOT WALKTHROUGH?”

if you miss one like i did, beat the game and max out your skills with enemy tides and start a new game. you can go thru again and get the one you missed, you do not have to get all 21 again in a single game. (you also start the new game with all your maxed stats, making enemies a breeze.)

One random tip here, if you do miss one, you can go to your xbox dashboard, system settings, memory settings and you should have an autosave and an autosave backup.

You can safely delete the autosave and then the next time you launch it asks you to restore the backup, which is usually at the reflecting pool the last time you saw the chick, Razia. You may lose 30 min. of progress, but it's better than a replay!!!!!!

Credit of this video goes to AchievementHunters/Rooster Teeth. *BEWARE* If you miss one sarcophagus, you will have to redo the whole game since there are no "start from this level". Otherwise pretty simple to find.

Credit to ugli - You don't always have to redo the *whole* game.
Say you miss just the second one. You only need to play the second playthru till you get that. The collectibles stack on multiple playthrus.