The Target is a quest in Build A Boat For Treasure. The objective of the quest is to hit a large target located at the edge of the Building Space. The building area is shortened. Under the target is lava, which can burn players' limbs.
"Hit the target to get 50 brick blocks, 150 gold, and 2 thrusters! Quest rules: You must build behind the yellow line. You may not attach blocks to your avatar."
Build a bridge like structure to it, try using a platform at the bottom to hold down the truss going up.