The large heated area on the right is simply where you pick up the sniper rifle. But here's where the more seasoned shooters go to hide afterwards.
Sniper Nest #1: A stairway leads to this one open notch. Look up and you're sure to find a crouched coward every time.
Sniper Nest #2: The windowed balcony between the base and the beach has multiple nooks for snipers.
Sniper Nest #3: Coming all the way up here is a bit inconvenient, but removing the entrenched sniper could save a ton of lives.