Follow down the path (#1) from the place where you've found the object - you'll come to brown spawning pit. Keep walking and you'll come to the edge of a chasm (#2) Jewel will jump across. There are still some worms in the sand so exterminate them to get the last tower object. The nest with eggs is in the alcove to your right. There are 3-4 worms to kill on the right and one more to the left so go ahead. It's a tough job so be patient.
Now turn right and up there for the last tower object (#1). Take it to the waypoint and go back to the chasm. Go left and fight the raiders. There's blood pit to your right so use it if you need. Then send one of these blaster beetles to the bony barrier (#2) - you might need 2 eggs to do it so take one as far as you can to lure the bug and go quickly to grab another one and run with it to the barrier. The barrier to your left hides a way to some loot - but you'll have to kill another worm for it. Behind the barrier to your right there's a wheel to open the entrance to the tower across the chasm. You'll need reds to kill the first bug - luckily there's red spawning pit near by.