Yamata Ruins

The Yamata Ruins (ヤマタイ遺跡, Yamatai Ruins)are located beneath the city of Yamata.

Background
The Yamata Ruins are first visited after Himi joins the party. At the request of Susa, Himi and Matthew travel to Uzume's grave to allow Himi to pay her respects. Uzume's spirit reacts to Himi's presence, and not only tells of Himi's purpose, but also hints at the ruin's existence. Matthew discovers the entrance with the assistance of Himi's Search Psynergy. Initially, however, the party is unable to explore the ruins fully. However, after gaining the Red Orb from Unan, Himi has a vision that reveals the Ruins's purpose: the ruins hide the Yellow Orb, needed to access Apollo Sanctum. Since the Adepts now possess the Red and Blue Orbs, needed to explore the ruins and reveal the Yellow Orb, the Adepts return to the ruins, solving its puzzles and eventually gaining the Yellow Orb.

First Visit
Once the player enters Uzume's tomb with Himi, a cutscene will trigger. After the scene, use Move on the large rock to reveal a platform. Use Himi's Search to reveal a transporter, which leads into the ruins.

Two chests appear in the first room, the left holds the Masamune, while the right holds a Water of Life. Going into the next room, a large tablet appears. Reading the tablet reveals that two gems will be needed for the "eye of truth" to open. The next room, off to the right, has a red tablet that states:"The crimson gem points the way to the one who sleeps beneath the land." Since the no such gem appears in the player's possession at this time, return back to the main entrance.

Second Visit
Go back inside and check the red tablet. The sand will fall, letting you climb downwards. Move down and past the first room into the second one. Here, push the middle column into the left spot, the right one into the middle, and the left one into the right spot. Jump on the glyph and examine the tablet to lower the sand again.

Good, now jump back on the glyph. Go down and "Search" the glittering spot to find another glyph. To get the chest, you need to move column number 3 into the middle spot and column number 1 into the right spot. Do so to acquire the Thunder Crown, which is cursed. Go into the previous room and use the glyphs to continue. Head past the planks into the next room. The tablet here tells us that we'll be rewarded for all of this!

Keep going into another block room. Here push the right block to the right so you can get up to the next level and use Search to make another glyph appear. Go back down and move the right column to the left to line up with the up and down line, then move the middle column into the left slot and the last one into the remaining slot. Use the glyph now and examine the blue tablet to sink the sand some more. To get the Venus Djinn down there, go down to the columns. Now put the middle column into the right and then push the right column over to the left like we did before. Ride the glyphs now to grab the Venus Djinni Hemlock. Retreat to the previous room and go down the ladder here and use the stepping stones to reach the chest with the Cookie. Now go back up the ladder and use Grip to get over to the left exit. Examine the last tablet to sink the sand all the way. Now backtrack until you get to the gold tablet, where you can go even further down as you can see. Move through the door, jump on the glyph and watch the scene for the final orb.

Retreat back to the previous room and read the yellow tablet. This will cause the sand to sink further and lead the way to the Gaia Blade. Use Search to make the chest appear.

With the last orb, we can unlock the gate at the Endless Wall and make our ascent towards Apollo Sanctum, but we need the Umbra Gear to do much there.

Collectibles

 * Thunder Crown
 * Venus Djinni Hemlock
 * Cookie
 * Gaia Blade
 * Masamune
 * Water of Life