The Stone Bridge is located directly to the right of the center of beach on Archeon Temple Ruins.
After Dr Cornelius requests for the player to repair the Stone Bridge the player may approach it to see the requirements.
After selecting to to repair an option to use 21 Pearls is offered to speed up the process.
The entire process will take 12 hours to complete if it is not sped up.
Once the construction is complete a tent is placed over the space the broken Stone Bridge was and a bubble with a hardhat and sledge hammer appear.
After tapping the bubble the Stone Bridge is revealed.
Once the Stone Bridge is revealed the player must talk to Dr Cornelius again.