@EventHandler
    public void onMove(PlayerMoveEvent event){
        Location l = event.getPlayer().getLocation();
        Vector v = l.toVector();
        Location pt1 = new Location(Bukkit.getWorld("world"), 0, 0, 0);
        Location pt2 = new Location(Bukkit.getWorld("world"), 100, 100, 100);
        if(v.isInAABB(Vector.getMaximum(pt1.toVector(), pt2.toVector()), Vector.getMaximum(pt1.toVector(), pt2.toVector()))){
            Inventory inventory = Bukkit.createInventory(null, 9*3, "Stuff");
            inventory.setItem(0, new ItemStack(Material.STONE));
            event.getPlayer().openInventory(inventory);
        }
    }