The girl in front of the ancient ruins saw it on the roof there. To reach it, push the big rock to the right until you can jump to the vine. When you reach the platform, jump left onto the roof.
It's on top of the ruins
on top of the ancient ruins
Swim right to the island to rescue the missing boy. Lead him back to the beach.
On Shark Tooth Island, the translation key is the missing page atop the ruins. On Nabooti Island, the Sphinx symbols are all matched, not translated. (see related questions)
on top of the bulding where the cocanuts fall
open. that's the answer. OPEN.
You have to collect all the pieces of the missing page of the journal.
on top of the cave in the Ancient Ruins
Shark tooth island is when you have to to save people from a giant shark
The missing page is on top of the ruins, and shows the translation you need to OPEN the door in the ruins. (Push the rock over to reach the vines, climb and jump to the roof.)
At the completion of Shark Tooth Island, you rescue both Professor Hammerhead and the missing boy, both trapped by the menacing giant shark. The "calming potion" (knockout drug) created by the medicine man puts the shark to sleep and you can swim out to the island. (see related question)
You get the translation paper and go to the cave its on the top left of the cave.