How to assemble a tower: Bolts on a tower go up and out. Meaning that the nuts for the bolts face the sky or away from the center of the tower. There are two reasons for this:
- If the bolts vibrate loose eventually they will fall out and the hole will be more readily apparent, then the bolt sitting in the hole and the nut is missing
- It is easier to inspect the nuts and the locking device on the nuts if they are facing outward
As far back as anyone I know of in the industry can recall, this started with Rohn brand tower drawings, specifically showing all the tower bolts facing up and out.
Bolts facing out:

Tower Bolts on bottom of tower
Bolts facing out and up.

Tower Bolts on Tower Mount