Back of the Cheese grater

Here I'm underneath the Lloyd's building and the main structure in the middle is what I believe to be the Cheese Grater.

It may not be its official name, but from the front it looks serrated, resulting in the given name.

So far we have the Gerkin, the Shard, the Cheese Grater and the Mobile Phone. I'll have to try to get some photos of all of them at some point.