The Focus Tower (フォーカスタワー, Fōkasu Tawā?) is a location in Final Fantasy Mystic Quest. It is a massive tower rising in the center of the world, and as its name implies, is a focus point of the game. Passage through the tower is the only way to pass between the four regions, and within it via a secret passage is the entrance to Doom Castle, the final dungeon and lair of the Dark King.
Standing atop a plateau at the junction of the four regions, the Focus Tower is entirely devoid of monsters but contains several chests containing magic spells and armor. The in-game dialogue implies the Focus Tower was once used freely by the people of the world as a place through which the other regions could be reached, until the Vile Four sealed the doors of the Focus Tower using magical coins. As Benjamin kills the Vile Four and retrieves the coins, he can open the tower's doors and explore the next region.
Late in the game it is revealed that the Focus Tower houses, or acts as a conduit, for Doom Castle, the Dark King's stronghold. Using Captain Mac's ship, Benjamin sails to a secret entrance to the tower at the foot of the cliffs below and accesses a part cut off from the rest of the tower, entering the upper floors of Doom Castle where the Dark King lies.
- There is a Hidden passage in the first basement, located near the entrance of Focus Tower when entering from the Earth Region. It acts as a shortcut to reach the stairs leading to the first floor of the tower.