Monte d'Or is the main location set in Professor Layton and the Miracle Mask. It is a large city that was made rich thanks to Henry Ledore's golden find. It is located in the middle of the desert and was founded 18 years before the game was set. The city started off as a small inn located near an oasis (The Reunion Inn), and has since developed drastically thanks to the fortune of the golden find at the Akbadain Ruins, whilst Henry looking for Randall Ascot. He brought Angela Ledore and Mrs. Ascot to Monte d'Or to aid him in the search for Randall.
Prologue: The Dark Parade
When Professor Layton, Emmy and Luke get to Monte d'Or, they are just in time for Monte d'Or's festival. Layton and Luke decide to stay to watch the festivities, while Emmy separates from the two to conduct her own investigations. Suddenly, Layton and Luke find themselves almost alone on the street after the residents and performers flee the street. The reasoning to this was made clear when the Masked Gentleman appeared on the top of a roof. He started performing his first 'miracle' of turning people into stone. Emmy reunites with the two and altogether they pursue the Masked Gentleman on horseback, however their efforts are cut short when the Masked Gentleman throws smoke bombs at the trio, allowing for his escape.
 Places of Interest
 Dromedary Hotel
- Main Article: Dromedary Hotel
The Dromedary Hotel, run by Pascal, is located on the western side of the city, and is Professor Layton's, Luke's and Emmy's base of operations. The hotel is easily distinguishable by the large sign with a camel on top that stands outside the hotel. It stands between the City Monument and the One-Ring Circus.
 Ledore Mansion
- Main Article: Ledore Mansion
The Ledore Mansion is the residence of Henry Ledore, Angela Ledore and Mrs. Ascot, and stands in the residential area of the city on the east. Professor Layton and the team are directed here after witnessing a miracle of the Masked Gentleman's for the first time. Angela can always be spotted in the mansion's parlor.
 Dalston Mansion
- Main Article: Dalston Mansion
The Dalston Mansion is the residence of Alphonse Dalston and his butler Gonzales, located on the western outskirts of the city. Professor Layton and the team are directed here when Angela Ledore raises her suspicions of Dalston being involved with the Masked Gentleman and his plans.
 Reunion Inn
- Main Article: Reunion Inn
The Reunion Inn is the largest hotel situated in Monte d'Or, and is the foundation of the city's development. A tram is required to reach the hotel. Professor Layton and the team go here after hearing of the Masked Gentleman's appearance at the hotel.
 City Hall
- Main Article: City Hall
The City Hall is the main hub of the special task force tasked with investigating and apprehending the Masked Gentleman, located to the east of town. It is situated between the Ledore Mansion and the Racetrack. Professor Layton and the group travel here after they hear of the special task force and wish to contact them.
 Monsarton Gallery
- Main Article: Montsarton Gallery
The Montsarton Gallery, run by Artie, is home to the city's artwork, which lies in the south of the city. The gallery is inaccessible at the start of the game due to investigations being held after accusations of paintings coming to life. The gallery stands between Knickknack Alley and the Merchant District.
 Pumpkin Park
- Main Article: Pumpkin Park
Pumpkin Park is the city's theme park, located in the western area of the city. The park has many rides that are mainly pumpkin themed, paying homage to the name. The Masked Gentleman makes an appearance here to perform one of his many miracles.
 One-Ring Circus
- Main Article: One-Ring Circus
The One-Ring Circus, run by Tyrone, is the most famous circus in Monte d'Or, located on the western side of the city. The circus is fully funded by Alphonse Dalston, who comes by daily, mainly to visit Maurice. Professor Layton and the team often see the performers of the One-Ring Circus scattered around the city, promoting the show.
- Main Article: Racetrack
The Racetrack is a popular tourist attraction in the north-east of Monte d'Or, where tourists often visit to bet on horses, and is located past the City Hall. Professor Layton and the group visit the racetrack in order to conduct their investigations into the petrification miracle that had taken place the night before.
 Scorpion Casino
- Main Article: Scorpion Casino
The Scorpion Casino, owned by Drake, is Monte d'Or's largest casino that is located to the west of the city. Professor Layton and the team are rushed there after word spread about a sort of commotion going down at the casino, with suspicions it was the Masked Gentleman. It only turned out to be Frankie causing an argument with the casino owner, however.