Winx Club Forever
The Red Tower is the entrance to the Golden Kingdom. It door is a regular sized door with magical inscriptions written on them. The doors continue to get smaller with the last being miniature-sized, a precautionary to those whose hearts are filled with darkness. Preventing those selfishly seeking the might powers protected by the Golden Kingdom.
The tower is a mahogany wood appearance with the top having a more rectangle feature. Further down the tower has more indentations with two square structures. From there, roots encircle the tower and forms the tower's main body and foundation. There are stairs that lead to the door. The designs the encompasses the door is where the structure is indented, curving inward. The door is well decorated, sectioned off with three layers before the actual door. The layers maintain the wood patterns but the first layer is a brighter brown color, then a dark brown, then a tannish-green, with the final door appearing to be more of a golden-wood color.
With every door that is opened, the entrance gets deeper into the tower. The first door has multiple sqaure patterns with a simple turning knob. The second door bares wood-striped patterns with a lever. The last door that leads to the Golden Kingdom is the smallest and much more decorated. Golden mystical text is on the door's face with golden swirls bordering it. The door can be simply pushed opened if the person(s) are deemed worthy.
In "The Red Tower" it is first mentioned by Tecna when she tells the Winx about the Water Stars, the opposing force of the Dragon's Flame, and their location: the Golden Kingdom. The Red Tower is this kingdom's doorway. The tower itself is located in the Veil Mist Forest, the moment this forest is mentioned, the pixies are unnerved, as according to Chatta, it is a dangerous place as it is past the Barrier Mountains.
Nonetheless, the pixies, Winx, and Specialists (minus Helia and Riven) head to the Veil Mist Forest to search for it. After a crash landing into the forest, the pixies lead them to the tower but then leave as it is much to dangerous for them to go further. The rest head to the tower's door. Flora opens the doors until she reaches the smallest one with inscriptions. But before she can read it, pterocentaurs ambush them.
After dealing with the pterocentaurs and clearing up the misunderstanding between Ophir (who was a stow away but helped the group) and Riven (who assumed Musa was kissing him from a video sent by Flora), they return to the tower's door. Timmy examines it but cannot read it due to the mystical text. But Bloom can and it reads "Only magic creatures of noble heart and pure soul may enter."
After some thinking, the girls conclude that using their Fairy Dust to remove darkness from their souls. All (except Bloom whose Enchantix is incomplete) were able to miniaturize once they sprinkled the dust onto themselves. Tecna opens the door and the girls precedes through it.