Yold Ruins

The Yold Ruins are the setting of Chapter 1-4 in Super Paper Mario.

A Brief Description
There are many locked and out of reach doors within the ruins, requiring the player to be creative in order to find out how to reach them. One puzzle in particular requires the player to let hundreds of Spiky Tromps onto one platform, then step onto a switch in order to drop them all below so that a doorway may be reached. At the end of the ruins, the player encounters Fracktail, a robotic dragon. While at first he intends to let the player pass, Dimentio short-circuits him, making him go crazy and attack Mario. Once defeated, Mario receives the Pure Heart from Merlumina.

Chapter 1-4: Monster of the Ruins
As was his trek through the Yold Desert, Mario's adventure in the Yold Ruins had little of interest. He encountered dozens of Buzzy Beetles; however, they acted little more than as cannon fodder, seeming to practically beg to be thrown into each other by Thoreau. Mario encountered for the first time a smaller version of a Spiny Tromp, the Spiky Tromp. In fact, at one point at switch unleashed hoards of them; not to worry, though. Mario simply hurried off and pressed down a giant, red, rusty ! switch, dropping all the Spiky Tromps into a pit and allowing him to continue.

Eventually, Mario reached the roof of the vast ruins. There, he met the fierce Fracktail, a robotic dragon whose sole purpose was to protect the Pure Heart from lawless theives. However, Fracktail identified Mario (with his "Level 5 Mustache," as Fracktail put it) as the hero, and gladly let Mario continue on to the Pure Heart.

All was not well, however. Dimentio, unhappy with Mario winning so easily, attacked Fracktail. Fracktail malfunctioned, and, changing Mario from a Level 5 Mustache to being at a danger level of a Level 1 Jelly Roll, attacked the plumber. The two waged battle, but Mario emerged victor; Thoreau was proving to be a big asset indeed, and without his help Mario would have been cyberdragon food.

Fracktail destroyed, Mario hustled to a newly appearing door. Inside and down a few steps was the deceased holder of the Pure Heart, Merlumina. Merlumina had waited 1,500 years for Mario to come--dying as she waited--and so her ghost was very happy to see that the hero of legend had finally shown his face. After telling the "short" version of the story of why Pure Hearts could stop the Void (in typical Shaman fashion of it being extremely long and boring, despite being a short version this time), Merlumina handed the Pure Heart over to Mario. Pure Heart in hand, it was now time for Mario to reveal the door to the Gloam Valley...

Enemies

 * Buzzy Beetle
 * Spiky Tromp
 * Squig
 * Squiglet
 * Fracktail (Chapter 1 Boss)
 * Frackle

Trivia

 * There are various nods to the Dry Dry Ruins in the Yold Ruins. One of the more obvious ones is the high amount of Buzzy Beetles.  However, a more subtle one is that they both featured at least one large, rusty switch that would slowly lower, making something sink (sand in the Dry Dry Ruins, Spiky Tromps in the Yold Ruins).
 * Throughout the Yold Ruins--and especially in the room directly before Fracktail--one may see the faint, aged depiction of Fracktail on the walls. In the room directly before Fracktail, this is most visible; the tail begins at the door at the bottom of the staircase, and the head is behind the Save Block at the top.