Dude, it uses diamond. What's the point?

[edit] Oh wait, I just realised it's not all about destruction in this. Awesome SHLD-gate system dude, seriously.

Once it's closed, it's supposed to end the world while whoever is in is safe. And it's never supposed to open, as the entrance gets stackpiled with sand and rock.

Its an effective bunker

You can't get out! Remember PHOT, WATR, HEAT and PLNT!

I like it!

things need light, heat, food and water to survive, no? the PHOT is light, keeps the PLNT, the food source alive (read: photosynthesis), WATR is the water, obviously, and HEAT is equally self-explanatory. Because one cannot escape from it, one should tend to make sure that one has these very basic of supplies.

dude i cant walk in when gate is open...

luv the idea of the sheild

cool gate idea