On Abandoned Aqueduct there will always be 2 hidden buttons, which when pressed at the same time will open the closed gate, I won't spoil what happens next ;).

Here are all of the possible button spawns:

Here are a few ways you can press one of the buttons.


The first way to press a button is to play as captain and place one of your beacons on a button, which means you'll have to sacrifice one of them, but it is absolutely worth it.


You can also play as engineer and place one of your turrets on a button.


Now onto the most tricky tech out of them all, you can press the button using your pylon as loader, it is pretty hard to pull off, but it is possible.
Also keep in mind that the pylon will vanish after some time, so better find the other button first before doing this.


And last, the most well-known tech ever, the pot rolling.
It is the most reliable one, since you can do it as pretty much every survivor, it does take some skill to pull off consistenly however, so get rolling!

Also if you're playing multiplayer you can ask one of your teammates to stand on one of the buttons, just wanted to point it out.

If I missed something, let me know!