St. Mystere is a small town founded by Baron Reinhold as a place for his daughter Flora to stay so she wouldn't be lonely after he passed away, and in hopes that a worthy foster parent would someday find her and take care of her. It is the setting of Professor Layton and the Curious Village.
Baron Reinhold was a wealthy man who loved his daughter, but due to his failing health he knew that he would soon be forced to leave her behind. In order to leave her in a place where she would be well taken care of and never lonely, he commissioned his engineer Bruno to create a town inhabited by robots. Bruno had already created Matthew and Dahlia for the Baron and therefore set to work creating many more robots. When the Baron passed away, The Tower was built in the middle of the city and Flora was left to wait until a worthy foster parent came to find her.
Sometime later, Professor Layton and Luke are sent a letter from Lady Dahlia, requesting that they help with an inheritance dispute her family is having in the wake of the Baron's death. Professor Layton and Luke arrive in the village and set about solving the mystery of the Golden Apple, which is at the center of the dispute. They eventually conclude that the Tower has important clues as to the whereabouts of the Apple and go there, meeting Bruno and discovering the truth behind St. Mystere's residents. After ascending to the top of the Tower and meeting Flora, Layton realizes that the Apple is, in fact, the girl herself.
However, Professor Layton's self-proclaimed nemesis Don Paolo arrives and attacks the Tower, causing Luke to be separated from Professor Layton and Flora, who devise a hanglider to use in order to escape the crumbling building. They land safely and return to Reinhold Manor where, after solving one last puzzle, the Reinhold fortune is revealed. However, touching the fortune will cause the inhabitants of St. Mystere to cease operation, and Flora ultimately decides not to take any of it. Instead, she leaves the village with Professor Layton and Luke, leaving her father's last gift to her, the village, intact.