While driving underneath the ocean, these silos are sort of the breathing points. I thought I would get a headache or pass out, but there are signs that say these things are ahead. Generally speaking they are a mile or two apart so I can hold my breath for a long enough time.
The shininess you see is unknown, but I would guess it is water. Look at those tunnels, that isn't metal you're looking at, its concrete. The shear engineering here blows my mind away.