Subcon

Subcon (sometimes called Sub-Con) is a peaceful dream world of the Subcons.

''Super Mario Bros. 2
Subcon is the setting of the game Super Mario Bros. 2. Subcon was once a peaceful place, until it was taken over by the tyrannical frog king Wart. Wart captured and enslaved the Subcon fairies, the protectors of the realm and imprisoned them so that they would not interfere with his evil plans.

Inside their confinement, the Subcons sent a message to the hero of the near-by Mushroom Kingdom, Mario, to come and deliver them from the dictator. At first Mario thinks the message is just a dream, but the next day, while on a picnic with Luigi, Princess Toadstool, and Toad, he discovers a cave that leads him to the very world he saw in his dream.

Mario and his friends instantly set out to free the fairies. They battled their way through Wart's army, the 8-Bit Club, and his generals: Birdo, Mouser, Clawgrip, Fryguy, and Tryclyde. In the end they faced the evil king himself, and was eventually able to defeat him and free the captive fairies. They then awaken back to the Mushroom Kingdom.

Super Mario Advance
In the Remake of Super Mario Bros. 2, there were Yoshi Eggs scattered all around Subcon, which Mario has to recuperate all of them. It may be possible that the Yoshis lived in Subcon or visited through their dreams.

BS Super Mario USA
Subcon is again the setting of the psuedo-sequel of Super Mario Bros. 2 for Stalleview, BS Super Mario USA. Years later after the events of the invasion in Subcon, the world was peaceful at the time. The king of Subcon had made golden statues of the whole world's hero Mario as a thanks for saving Subcon and the inhabitants from the evil frog king Wart.

Suddenly, Wart returned to Subcon, after his "vacation" on Koholint Island in The Legend of Zelda: Link's Awakening, attacking it, including the king, scattering the golden statues of Mario all around the world by giving them to the generals of the 8 bits.

Finally, Mario, Luigi, Toad and Princess Toadstool returned in the world to save it from Wart's reign, fighting the 8 bits, the leaders, retrieving the statues, defeating Wart several times. By doing so, they saved Subcon, its kingdom and the king. The world is at peace once again.

Physical Features
Red plants stick out throughout Subcon, which, when pulled, will give the character an item (or occasionally, a Bob-omb). A lot of the region of Subcon is high in the sky; the "land" being clouds. Subcon also has a desert, snowy lands and grass plains. The only castle is Wart's castle, and no towns is seen throughout the game. According to BS Super Mario USA, Subcon has a kingdom and a king. Wart's castle from World 7-2 is the king's castle.

Trivia

 * The name "Subcon" is short for "subconscious".
 * In Yume Kojo: Doki Doki Panic, it was in a storybook that the kids Piki and Poki get pulled in by Wart and get locked in a cage. However, the Subcon world in that game was unamed like the storybook.