|Located In||Monte d'Or|
|Chapter Accessible||Chapter 3: The Battle for Monte d'Or|
|Residents|| Alphonse Dalston|
|No. of Hint Coins||4|
|East Exit||One-Ring Circus|
Dalston Mansion is the residence of Alphonse Dalston and is situated on the outskirts of Monte d'Or, in the game Professor Layton and the Miracle Mask. It is connected to the One-Ring Circus on the map. In the UK version of the game, it is also known as "Château Dalston".
A rusty gate stands outside the Dalston Mansion, with a stony fence surrounding it. Cacti are also dotted around the entrance to the gate. The mansion itself is dark in appearance, with several rooms and floors. The brickwork is of a dark blue color, with reddish-brown roofs. Several chimneys extend from the roofs of the house.
 Areas of Interest
 Dalston Parlor
The only room in the house that is able to be explored is the Dalston Parlor. You are let in here the first time when Dalston is free of custody, after being accused of aiding the Masked Gentleman.
The parlor's walls are made of brick, while the back wall is lined with windows, each with red curtains handing from them. A framed sword hangs on the back wall also. The floor is laid with a red and purple rug, and laid atop of them are dark green sofas and a wooden coffee table. A green doily lines the table, and two candelabras lay atop the table. A chandelier hangs from the ceiling, and a suit of armor sits along the side wall.
Chapter 3: The Battle for Monte d'Or
After talking to Angela Ledore about possible suspects behind the Masked Gentleman, she points Professor Layton, Emmy and Luke in the direction of Alphonse Dalston. When approaching the mansion for the first time, they are confronted by Dalston's dog, who snarls at the group.
After Dalston appears and tells the dog to retreat, Layton begins to question him about the Masked Gentleman. After denying his connections with the Masked Gentleman, Dalston's butler, Gonzales, comes rushing to hand a letter to both Dalston and Layton, in that the Masked Gentleman is to appear at the Gallery Plaza that evening.
Chapter 7: The Reunion Inn
When Dalston requests that Layton does not 'keep him in the dark' with the Masked Gentleman case, this helps Layton realize the trick that the Masked Gentleman had relied on when making the entire Pumpkin Park go completely empty for a temporary time the previous night.