Can anyone please help me identify what the fixing below is and how to remove it?
Four of them attached a wooden gate post to the side of a masonry wall. The wooden post is gone - it was rotten so came off with a crow bar. Now I'm left with these and they're very firmly embedded in the wall. Some have half broken off due to rust. There doesn't seem to be any screw or nail in the middle but maybe there is one and it's deeply embedded inside.