Map saint

[West]

Forau they walk there (on the stairs) like that, 'cause next to the stairs (where everyone usually camp; left to the screenshots) someone put a barrel, so Zombies are trying to get it, but they don't know how. It's a glitch used by some players. :V Same thing you can meet at map Store, when players put a barrel in a small gap next to the stairs.

About ladder - IDK what you mean, 'cause Zombies doesn't stuck there.