Monument Valley is a puzzle game developed and published by Ustwo Indie Games Studio in 2014. In the game, the player guides the protagonist, Princess Ada, through a maze of mise-en-scène and impossible geometric objects to reach the destination of each level. The game took around 10 months to develop, based on the concept drawings created by the company's game designer Youjian Wang.

Monument Valley is a fantastic adventure combining magical architecture and fantastic geometry. Explore hidden paths, discover illusions of sight and defeat the mysterious Raven Man to help the silent princess Ada out of the Monument Maze.

The game was generally well received by players. Critics praised the game's artistry and music, but found the game lacking in difficulty and the levels to be short. Monument Valley was the recipient of a 2014 Apple Design Award and was nominated for Apple's Best iPad Game of 2014. Over two million paid downloads were made in January 2015.

In Monument Valley, the player navigates the protagonist, Princess Ada, through various labyrinths of optical illusions and impossible geometric objects. These labyrinths are referred to in the game as "sacred geometry" and Ada travels through them in search of some kind of forgiveness. The game is presented in isometric projection and the player has to interact with the surroundings to find the hidden passages that lead to the end of the map. The game features ten levels with different central mechanics. Player interaction with the game includes moving platforms and totems, as well as creating bridges. The game guides the player indirectly through design elements such as colour, and directly through the Raven Man, who obstructs Ada's path. The game includes a camera mode where players can take screenshots on the way to roaming the levels and can use a filter feature similar to Instagram.