How to Unlock Tangaroa Tower Code
Okay, I'll assume you've reached the 3rd floor tower and found the Keypad, so. Open your journal (Press T). Go to Last Page.
On the page is a paper showing the words, underscores, and 4 images.
In the first column is the street name, the second is the code for the tower, and the third column is the building icon image, then to get the code, you have to go to the path listed in the first column, then look for the building that has the same icon in the third column, and the code is on the Building Number.
Then the format to find the code is [Street Name]_[Building Number]_[Building Icon].
Location Last Note and Blueprint Water Tank.