The Bowser Nightmare is a giant, evil castle-like gameboard structure formed from King Bowser's dreams, and it is the 7th board Mario Party 5.
As its name implies, this dark realm was created by Bowser's subconscious mind complete with towers, walkways, cannons, and a fountain. Similar to the Blooper Carrousel of Bowser Land, near the circle at the center of the board, this take players into the circle with Red Spaces and two Happening Spaces.
Heroes needed defeat 3 Koopa Kids Bowser, but at the same do not leave that easily. Similar with Magma Mountain, Bowser walk turning Blue Spaces into Red Spaces and crushes any player making them lose 10 coins when someone steps on a Happening Space close from his dome. The players near the flamethrower are burned and lose their Capsules for Bowser when someone steps on a Happening Space atop and Bowser forces the player to hit one of two surprise blocks when someone steps top-left and top-right sides of the board.
After player defeat 3 Koopa Kids, Bowser challenge it to Frightmare. With the Bowser's final defeat, this board disappears for good time.
- It is sometimes referred to as "Bowser Dream", "Bowser's Dream", "Bowser's Nightmare", "Koopa Dream", "Koopa's Dream", "Koopa Nightmare", and/or "Koopa's Nightmare".