How do I leave the mines?

[offensive mane]

When I go up the elevator I came down, the door is locked.

[Neko_Baron]

Can you not just jump on the boxes and crawl back out the hole? The door next to the lift isnt the way we came in, you might have to crouch first and jump to get into the hole. (its a pain), or did the other door somehow lock?

[Xitax]

Yes you can, but you have to crouch first. Low ceiling...

[AllayTheWolf]

You climb up the boxes the way you came in.

[Enter the Wang]

there is a tiny basket crate next to the larger crate that you need to crouch jump on first to get the extra height to mantle the larger crate.