Final Fantasy V/Earth Lithograph

Pyramids
At this point you can go north to Surgate castle, or further north to Karnak, but these towns have nothing new in them except updated gossip. Head west toward the Sand Tides; this time you must cross through a forest which is the last remnant of Moore Forest and there is a short cutscene where you pay your repects to Galuf at the Elder's Tree. When you enter the Sand Tides there is another short cutscene where you learn that the sand is no longer moving and it's now just plain desert. Continue west; if you keep going you eventually reach Moore Village, but there's nothing new but updated gossip here as well.

Enter the pyramid in the middle of the desert. This time there are two stone statues in front of the door to the pyramid. Check the door to start a battle with them.

When the battle the over, one of the pages from the Sealed Book floats to the door and burns up, thus unlocking the door.

It's a good idea to exit to the desert temporarily at this point to save and heal.

Pyramid interior
Before starting with the interior, you should be aware that many of the treasure chests here have monsters inside, so don't open them unprepared. Enter the pyramid proper and take the westernmost passage north. There are three buttons at the end which control an array of spikes on the floor. Press the buttons to arrange a safe path over the spikes; it's the left and right not not the center to be specific. If you step on the spikes you get poisoned which is no problem since a few antidotes will fix it. If you have a Geomancer in your party you can just walk over the spike with no damage at all.

Continue south through an arch, then east and let yourself be swept down the sandfall (i.e. waterfall only with sand). Battle for the treasure at the bottom, then make your way north fighting the snakes on the way. Go up the stairs to the east side of the first floor. Follow the passage east and south, then turn north and go past the sandfall to the 2nd Floor. Find your way through the hidden passages west, fighting more snakes, and go back down to the first floor. Open the sarcophagus to start a battle with GrandMummy, with the Hex Ring as a reward. Go back as far as the sandfall, press the button to make it stop, then continue back to the entrance. Since you're near the beginning again it's probably a good time to exit temporarily to save.