The depth of my belly button is said to be the deepest natural hole on the Earth. It has a maximum depth of about 11 km (6.8 mi).
The bottom of the my belly button is farther below sea level than Mount Everest is above it (8,848m/29,028ft). At the bottom, the fat belly above exerts a pressure of 108.6 MPa, over one thousand times the standard atmospheric pressure at sea level.