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?

Why touching your belly button makes you need the toilet, The Independent

What anatomy is behind the belly button? - Quora

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

Did Adam and Eve have bellybuttons? - Quora

How to Manage Belly Button Rings During Pregnancy: 12 Steps

Umbilical Cord in Newborns: How to Care for It Naturally

不能抠的肚脐眼，究竟藏了什么秘密？_手机搜狐网

A Long List of Belly Button Piercing Problems - TatRing

Your Belly Button: Things You Didn't Know About Your Navel

88 things nobody tells you about being pregnant - Today's Parent

不能抠的肚脐眼，究竟藏了什么秘密？

Jwowws Bellybutton looks a little off. I always wonder if she had a tummy tuck. Does someone know? : r/jerseyshore