I'll leave this here in case anyone else is looking for it. It was Juno Outpost.

Hi, I'm looking for a holdout map I remember from the original Alien Swarm, but don't remember the name.

You arrive outside some place, have to go around a corner, press a button, go back, then inside. (There may be some aliens attacking during a delay before you get inside. Or maybe that happens later when you go back out?)

There's a NS corridor, and a room with some eggs to the right.

You continue on in the short corridor, after a door (I think) there's a EW corridor, near the East end is another room to the south with some extras (and maybe eggs?), but the main idea is to crawl through a small, dark shaft, North, then West, into a bigger room where the main holdout takes place.

The main room has a slightly elevated place in the north, some gear lying around, 2 small, dark rooms to the south that you have to open somehow first, I think (sorry, don't remember details). You can also go from one small south room to the other.

I think there was a timer.

When you've spent enough time there, you have to go back out and get picked up by the shuttle or whatever it was.

I hope this is enough detail that someone remembers and can tell me the name, so I can find it in the workshop, or in my old files to at least to re-upload until the author does so.

I also think it was a pretty popular holdout map. Friends kept wanting to play it, but I wasn't that fond of holdouts or something.

Thanks for any pointers! :)