A self-building MOUNTAIN!  Made with command blocks!  Place a command block /give (name) command_block  and a lever next to it . Put this command :  /summon Item ~ ~3 ~
{Riding:{Riding:{id:"FallingSand",Time:1,TileID:137,DropItem:0,TileEntityData:{Command:"/summon
FallingSand ~ ~15 ~
{Time:1,TileID:72,Data:1,DropItem:0,Riding:{id:\"FallingSand\",TileID:137,Time:1,DropItem:0,TileEntityData:{Command:\"/setblock
~ ~1 ~
air\"},Riding:{id:\"FallingSand\",Time:1,TileID:137,DropItem:0,Motion:[0.9,0.9,0],TileEntityData:{Command:\"/summon
Item ~ ~5 ~-1
{Riding:{Riding:{id:\\"FallingSand\\",Time:1,TileID:137,DropItem:0,TileEntityData:{Command:\\"/summon
FallingSand ~ ~15 ~2
{TileID:1,Time:1,DropItem:0,Motion:[0.0,0.9,0.9]}\\"}},TileID:72,Time:1,DropItem:0,id:\\"FallingSand\\"},Item:{id:1,Damage:0,Count:1},Age:5979}\"}}}}"},DropItem:0},id:"FallingSand",Time:1,TileID:72,DropItem:0},Item:{id:1,Damage:0,Count:1},Age:5979}

AND PRESS THE LEVER ABOUT 10-15 times!