Help Giant Hole IN My World Really Creepy Minecraft?

So i Was Working In my World
And I Made Withers Everywhere
One Shot A Hill of Sand then It fell
After Getting Rid of Tons of Water With mcedit I noticed That There's a gold Block That Was there i Almost Had A Heart attack
So What Is it
I DIDN't DESTROY OF BUILD ANY OF THIS I SWEAR TO JESUS MO MODS OR ANYTHING Just MCedit To Get Rid Of A TOn Of Water In there Added (1). This Is A 1.5 World in Beta I Noticed Lights in an Orderly fasion You Can See 2 Of Them
I Also Noticed a Air Hole with String in it