|Game board is in||Mario Party 6|
|Star Space type||Fixed|
|Green Space Effect||Varied|
|Availability||Available from the start.|
Castaway Bay is one of the 6 board maps in Mario Party 6. The way this board works is almost exactly like Mario's Rainbow Castle in the original Mario Party in that it is a one-way map with junctions that re-unite at some point before the end of the board. Like with Mario's Rainbow Castle, the goal was to reach the end of the board when Bowser was on the other end so you could get Stars. Players would need to reach DK to trade in 20 coins for a Star. DK, would then give the player a ride on his boat back to the Start space. Bowser would give the player a Ztar that would cost the player 1 Star.(20 coins if the player had no Stars at the time)
The Green Spaces would have a different effect depending on where you landed on them. Landing on a Green Space at any port would cause DK and Bowser to switch spots much like the Green Spaces did in Mario's Rainbow Castle with Toad and Bowser. Landing on a Green Space on the first island would cause a Ukiki to come down and ask you to play a game. In the game, you would have to grab as many coins as you could while avoiding the small spike balls mixed in(much like the pond game during the day at Snowflake Lake except you're the only one getting coins) Landing on a Green Space on the 3rd island would have the player pay his/her respects to the Great Mushroom Spirit in order to try and get Orbs or even coins. At night, it would turn into a Giant Goomba Statue and it wouldn't matter if the player payed respects to it or not. Paragoombas would swap the positions on the board of all players.
There were a few day/night effects on this board. DK and Bowser would switch every time the time of day changed. There would also be an alien around the DK/Bowser spaces on the board. Lastly, a Pink Boo would also lend her services to players at night.(much like Towering Treetop)