East Gerudo Ruins Cave is south of Gerudo Canyon Skyview Tower and north of East Gerudo Chasm.
Cave Location
East Gerudo Ruins Cave can be reached by going down the sand whirlpool at -2694, -2809, -0053, which is south of Gerudo Canyon Skyview Tower and north of East Gerudo Chasm. This whirlpool is in the center of the circle of statues in the eastern part of the Gerudo Desert.
Cave Features
Quicksand is flowing counterclockwise around the area where you enter the cave. If you stand on the quicksand, you will rapidly lose stamina, so to cross the quicksand you need to reach solid ground as quickly as possible.
To the west of the sand pile where you landed when you entered the cave, you will find pieces of wood piled up against some bars in the wall.
East of the sand pile where you entered, there is a large statue head across the quicksand. Make your way clockwise from that statue. You can take one of the large wooden boards and move it across the quicksand to where the statue is, then move it back toward you, then stand on it and use Recall to have it take you across to the statue.
From there, make your way clockwise. There is a Shock Like in the southern part of the area that is guarding a rare ore deposit. Farther clockwise, there are some broken boulders in a small hole in the southwest wall. Break them open and climb up to that tunnel, and you will find this cave's Bubbulfrog.
Near that tunnel, you can look down at the quicksand to see a statue. Near that statue, there is a chest that contains a Topaz.