I've always wondered: what's behind the belly button?

We're constantly told what not to do with it, but what exactly is behind this mysterious orifice?

8 Weird Things You Didn't Know About Your Belly Button

Самые знаменитые влюбленные»: королева Виктория и принц Альберт

I've always wondered – News, Research and Analysis – The Conversation – page 1

UPDATED: My belly button has popped out and I'm not pregnant. Is this normal or am I dying? Seriously. – The Bloggess

I have some weird body odor right now, what's going on?

The Wonder Down Under: The Insider's Guide to the Anatomy, Biology, and Reality of the Vagina: Brochmann, Nina, Dahl, Ellen Støkken: 9781681440217: : Books

I've always wondered: what's behind the belly button?

What's really going on behind your belly button

So, I have an abnormally deep belly button. This is what happens if I don't keep it clean and dry. : r/WTF