A "Your Sanctuary" location is, in EarthBound, a special zone where the protagonist Ness can see visions of his past. By feeling a connection with his younger self, he is able to record a melody in the Sound Stone Buzz Buzz gave him at the beginning of the game. To truly understand his mind, Ness needs to collect eight melodies from these locations in the Sound Stone so that he is able to travel to Magicant. Each of these locations are guarded by a boss who appears in the map as a shiny light.
Giant Step is the first "Your Sanctuary" location, found near Onett. Ness must first beat Frank Fly in order to get a key to go through a shack and reach Giant Step. The boss guarding this location is the Titanic Ant. Here, Ness has a glimpse of a small, cute puppy before recording the first melody.
The Titanic Ant is an overgrown antoid creature who guards, along with its smaller ants, Giant Step. It can bite or cast PSI to create a shield, reduce Ness's defense, or drain his PP. Being the first sanctuary boss, it always battles Ness alone, and it starts the battle with two Black Antoids.
(+) Max HP: 235 - Max PP: 102 - Offense: 19 - Defense: 23 - Speed: 6 - Guts: 9 - Exp.: 685 - Money: $150 - No chance of getting an item.
Lilliput Steps is the second "Your Sanctuary" location, near the Happy Happy Village. After the city stops being blue and Mr. Carpainter is defeated, a cave that leads to the sanctuary becomes accessible. The Mondo Mole guards this location. Here, Ness has a vision of a baby in a red cap.
Mondo Mole is the second sanctuary guardian. It is a giant mole with a scary look guarding Lilliput Step. In battle, it can bash, tear into the target, claw with its sharp nails, and cast PSI to produce shields, heal itself or increase its offense. If it is found after Paula is rescued by Ness from the Happy Happyists, both of them fight Mondo Mole.
(+) Max HP: 498 - Max PP: 161 - Offense: 37 - Defense: 50 - Speed: 9 - Guts: 15 - Exp.: 5791 - Money: $400 - No chance of getting an item.
Milky Well is the third "Your Sanctuary" location, near Saturn Valley. Once Master Belch is defeated, Ness and his friends can go to Milky Well. The boss guarding this location is the Trillionage Sprout. Here, Ness thinks he hears his mother from far away saying "Be a thoughtful, strong boy".
The Trillionage Sprout is the guardian of the third "Your Sanctuary" location, Milky Well, found near Saturn Valley. It is capable of bashing, diamondizing characters with its eyes, and casting PSI Flash, PSI Shield and Paralysis.
(+) Max HP: 1048 - Max PP: 240 - Offense: 54 - Defense: 88 - Speed: 16 - Guts: 21 - Exp.: 30303 - Money: $1358 - No chance of getting an item.
Rainy Circle is the fourth "Your Sanctuary" location, found in Winters. Jeff passes by the boss of this sanctuary when he first appears but it can only be entered with Ness in the party. Shrooom! guards this location. Here, Ness catches a whiff of his favorite food, but just for a second.
Shrooom! is a giant mushroom put in the entrance of Rainy Circle, the fourth sanctuary, in Winters, and serves as a guardian of said place. It has a high defensive stat and poor defense, and it can bash, disrupt a characters's senses, mushroomize the party or heal itself with PSI.
(+) Max HP: 1700 - Max PP: 112 - Offense: 95 - Defense: 154 - Speed: 18 - Guts: 32 - Exp.: 96323 - Money: $4086 - No chance of getting an item.
Magnet Hill is the fifth "Your Sanctuary" location, found after a sewer tunnel that leads to the back room of the dinosaur museum in Fourside. The group must give the curator blocking the way a signature of the popular singer Venus in order to be able to pass. The boss guarding this location is the Plague Rat of Doom. Here, Ness sees a baby's bottle, but just for an instant.
Plague Rat of Doom
The Plague Rat of Doom is an overgrown rat found in the sewers of Fourside, and at the same time guarding the path to the fifth sanctuary, Magnet Hill. It can grin, bash, bite or try to poison characters with its poisonous fangs. Like Shrooom!, it possesses a strong defensive stat and poor defense, in addition to a relatively low offense stat but high critical hit chance. The Plague Rat of Doom is the first sanctuary boss not to utilize PSI.
(+) Max HP: 1827 - Max PP: 60 - Offense: 71 - Defense: 180 - Speed: 19 - Guts: 250 - Exp.: 115272 - Money: $4464 - No chance of getting an item.
Pink Cloud is the sixth "Your Sanctuary" location, found in Dalaam. Three black rabbit statues block the entrance, but they are erased once the party gets the Carrot key. Thunder and Storm guard this location. Here, Ness has a short vision of seeing his mother when she was young.
Thunder and Storm
Thunder and Storm are a pair of beings tied together to guard the sixth "Your Sanctuary" location, Pink Cloud. In battle, they bash, rush in and intertwine, or use a Crashing Boom Bang, a strong electrical attack. While they can't be paralyzed, they are vulnerable to PSI Flash.
(+) Max HP: 2065 - Max PP: 70 - Offense: 111 - Defense: 178 - Speed: 21 - Guts: 35 - Exp.: 129026 - Money: $4736 - No chance of getting an item.
Lumine Hall is the seventh "Your Sanctuary" location, found after a long tunnel that links it to Tenda Village. Once Ness gives the Tenda the book Overcoming Shyness so that they are not timid anymore, they give the party access to the sanctuary. This location is guarded by Electro Specter. Here, Ness sees a vision of his father holding him.
The Electro Specter is the second-to-last sanctuary guardian, appearing before the entrance to the Lost Underworld. It can cause electrical shocks to the party, and also use the Shield Killer, Hungry HP-Sucker and Neutralizer items.
(+) Max HP: 3092 - Max PP: 80 - Offense: 148 - Defense: 203 - Speed: 29 - Guts: 47 - Exp.: 261637 - Money: $6564 - No chance of getting an item.
Fire Spring is the eighth and last "Your Sanctuary" location, found in the Lost Underworld. After reaching Lumine Hall the party finds itself in a giant world infested with dinosaurs, and they proceed to visit the last sanctuary. The Carbon Dog guards this location, and then becomes the Diamond Dog. Here, Ness has the feeling he was being watched by himself as a baby.
Carbon / Diamond Dog
The Carbon Dog is the sanctuary guardian of Fire Spring. It can howl, bite, charge forward, spew out a fireball, or shoot a spray of fire. When beaten, it transforms into the Diamond Dog, losing its fire powers and considerable Guts, but gaining PSI. Instead, it can howl, bite, use PSI Shield β, emit a light equivalent to PK Flash, or diamondize a character. In addition, once turned into the Diamond Dog, it starts with a physical shield.
Carbon Dog: (+) Max HP: 1672 - Max PP: 0 - Offense: 159 - Defense: 174 - Speed: 31 - Guts: 52 - Exp.: 0 - Money: $0 - No chance of getting an item.
Diamond Dog: (+) Max HP: 3344 - Max PP: 154 - Offense: 167 - Defense: 230 - Speed: 31 - Guts: 10 - Exp.: 337738 - Money: $6968 - No chance of an item.