The Tower of Darkness (Japanese: あくの塔Tower of Evil) is a landmark on the Isle of Armor in the Galarregion. It is one of the Towers of Two Fists, and it is where the player goes during The Isle of Armor Expansion Pass if they wish to evolve their Kubfu into a Single Strike StyleUrshifu. This can be achieved by defeating all the Trainers in the tower and having Kubfu examine the Scroll of Darkness on the top floor. The player is only allowed to enter the tower if Kubfu is the only Pokémon in their party. However, if the player doesn't have Kubfu in their party or Box, they can climb the tower with any Pokémon.
If the player chooses to train Kubfu here, the Tower of Waters becomes inaccessible to them.