The 39 Clues Wiki
The 39 Clues Wiki

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Sulfur is Clue #25 and is hidden inside the Hagia Sophia.


When the Janus branch became the leader of the Ottoman empire, they made a decision that they would hide the Clue in Turkey. They chose the prettiest place they had laid their eyes on--the Hagia Sophia in Istanbul. They hid it by blending it into the decorations in the building.


This Clue can be unlocked by completing the Turkish Delight Card Combo.

When viewing sulfur on 'your profile' at the Clue Hunt, instead of being green, the Sulfur symbol is red.




The screen shows the Hagia Sophia. Then, it zoomed in on the top of the roof, and showed in scan mode. The top decoration shows a Janus symbol. In the end, the symbol changed into sulfur alchemical sign with the word 'SULFUR.'

Sulfur crystals

Sulfur grains.