Ironclads and Concrete Bunker

[Tzan]

Its a roof hatch.
Like you might find on a submarine.
It can be locked from the inside so having a handle on the outside isn't a problem.

In Company of Heroes, the older version, you could upgrade base buildings to have machine gunners pop up thru hatches in the roof.

It was that or a satellite dish, but there were no satellites during WWII, that we know of.

I just wish they made slope/corner pieces at that angle, I couldn't find any.

The red bricks in the back wall are air vents and have those ridges on them.

[Warhead]

There can never be enough Ironclads in the world. Now you need to host a battle with these ships.

Nice bunker too.