Undercity Pharos

Undercity Pharos (Arcanian name, Tal'fa Palacaleo) is one of The Seven Wonders in Unlimited Saga. It's located underneath Iskandaria and is the final dungeon for Mythe

Unlike the other Seven Wonders, only Mythe, Ruby and Ventus can explore Pharos fully. The entrance to the Undercity is located in Iskandaria and can be accessed at any time without needing a quest. However, once you explore the entrance you find yourself trapped by large doors, sealing off the proper portion of Undercity Pharos of which only Silver Girl, and possibly Iskandar, can open.

It is also here that you will find, possibly, the hardest of the 7 final bosses.

Trivia

 * The name 'Pharos' is most likely a reference to the Pharos of Alexandria, one of the Seven Wonders of the Ancient World, while the concept and looks of the city itself seem to have been inspired by Plato's myth of Atlantis.
 * The only mystery remaining is how Pharr was able to enter the Undercity in the past. It would be possible that she had a companion from the Arcanian race, much like Mythe, Ruby and Ventus, but if such is the case, then one Arcanian would also be probably necesarry to enter the Undercity when Mythe and his companions first enter it during the game.
 * Saying the above theory is possible, it does not explain how Ruby is able to enter the Pharos. This is more likely due to the fact that Iskandar is connected to the ancient myths/scriptures, meaning that the requirements for entering the Pharos are not limited to Arcanians so much as those who had influence in the past, or those with great magical power.