Dizzy heights

I took this from our terrace, looking down on to one of the tall thin trees that grows in our garden. I still don't know what kind of tree it is - any ideas?

Dealing with a hungover Mark today, although he isn't as bad as he has been on return from previous stag do's. I remember after his own stag do, he smelt like bins for about 5 days. Not even stale alcohol... actual bins.