The Ruins is the first location seen in Undertale Yellow.
Toriel meets Clover after they encounter a Froggit in the second room. She will then guide them through the Ruins until they reach the switch room. Clover will fall through a hole that leads to the Dark Ruins due to a puzzle malfunctioning.
The Ruins have not changed from its Undertale counterpart, besides the malfunctioning switch room puzzle, and an added lower level of the Ruins called the "Dark Ruins."
The area is far larger than in Undertale, which suggests that a larger society of monsters had developed here before moving to New Home.
Dark Ruins Edit
The Dark Ruins is mostly composed of large rooms, water streams, bridges, and a small cave system with no illumination.
All of the new monsters are found and fought here, including the miniboss and area boss. The Dark Ruins is a secret lower level underneath the Ruins, which Clover accidentally enters after falling through a hole that was made by pulling the unlabeled switch in the Ruins.
The puzzles in the Ruins are identical to the ones seen in Undertale, the exception being that Clover can't proceed beyond the switch room.
Dark Ruins Edit
In the Dark Ruins, there are more puzzles than the ones shown in the first floor. These puzzles use different objects that can open doors, disarm spike traps, or otherwise grant Clover a passage into the next room.
The Second Switch Room Edit
The second switch room is a room with three switches on the wall, spikes that prevent the protagonist from entering the next room, and a plaque on the wall that reads "EXPOSITION" in large friendly letters.
In order to proceed, the protagonist must pull the third, first, and second lever in order. If done correctly, the spikes will disappear, leading you to the next room.
The First Glowing Boxes Puzzle Edit
This puzzle has five glowing boxes, with the first and the fourth glowing box turned off.
If you turn on or off any of these boxes, it will turn on / off the others at their sides. In order to complete the puzzle, the protagonist must activate the second, and then, the third glowing box. It will make all glowing boxes turn on and the protagonist can advance, leading you to the next room. If not, press the switch and the puzzle will reset.
The Second Glowing Boxes Puzzle Edit
This puzzle is similar to the first glowing box puzzle, except it contains ten boxes set up in a five by two fashion.
Starting off, the first and third boxes in the first row are on, along with the second, third, fourth, and fifth boxes in the second row. To solve the puzzle and be able to proceed, one must first press the second box in the second (The lowest row) row, then the third box in the second row, and finally the fourth box in the first row.
- The Ruins are the most elaborated location so far.
- The fact that the Dark Ruins are in a state of disrepair suggests that they may have been abandoned, and left in this state for a long time.