Air control tower
The only way into the platform is by way of a ramp that lowers from a watch post the Enclave set up in the old air traffic control tower.”— Paladin Tristan in the Lone Wanderer's orders.
A single sentry bot can be encountered on the ground floor, but the robot is easily avoided by sneaking upstairs. While in the tower, one of the flying Vertibirds may fire a missile through the broken windows. It will fly past the tower first, allowing time to shoot it with a weapon such as the Tesla cannon.
A Nuka-Cola Quantum can be found here. Immediately after entering, go right. The Nuka-Cola Quantum is located in the second cubicle, underneath the desk.