10 Secrets About Mark Zuckerberg's Hawaii Underground Bunker

Zuckerberg's Kauai compound boasts a panic room and tunnels linking various structures.

He's building a $100 million compound in Hawaii—complete with plans for a huge underground bunker.

It consists of about 12 structures, encompassing guest houses and facilities related to agriculture and ranching.

Images unveil a secretive panic room in Zuckerberg's Kauai compound.

With not many friends in Hawaii and growing isolation from the community, it seems the billionaire is fortifying his fortress.

The two main residences will be joined by a tunnel that branches off into a 5,000-square-foot underground shelter.

The entrance to the shelter is similar to those found in bomb shelters, reinforced with concrete.

The bunker will feature its own living space, a mechanical room, and an escape hatch.

The before and after pictures of the tunnels that are being constructed.

The property aims to be further self-sufficient with an 18-foot-tall water tank and the ability to produce its own energy and food supplies.