Once you get to Moonbrooke and progress to get the Spike Trap recipe and can build them, lay them along the hallway East of the Bell Room, (there's a room to the South that has a bit of water in it and a bridge across it. Once the traps are laid along that hall area (up to where the mobs spawn if you like), just stand on the wall and the monsters will keep attacking infinitely (so long as you don't progress the story further) standing on the wall will keep proccing the wave of monsters every ten or so seconds. The spikes will kill them easily and you won't take any damage. Your hunger doesn't go down if you stand still. You can level up to the island cap and do something else while it happens, it also makes for a great iron farming spot (if you didn't get the infinite supply from the Explorer Island).