Missile Silo. The link doesn't work right now but it looks like an upside down egg box with some additions, so inspiration.
Tin shed, roof comes off - orks - 40k
Old school bunker - Forum - DakkaDakka | Just a few skulls short of a throne.
Bunker built into a rock outcropping + nice mechanical bits.
Reinforced Heavy Bunker - Sci-Fi
Nurgle - great wear and tear!
Workin on trying to fix the Noxious blightbringer ft fewer bells and censers. #deathguard #New40k #warmongers