Strange, I have deleted a CalDAV (google) calendar in the past, I actually had created a new google calendar which didn't show up, so I figured I just delete the existing Caldav account.

After then seeing the calendar was really gone, I recreated it - just to find the new google calendar had still not been added - and then I realised I had to set google calendar up for use with my "iPhone"....

Anyway, no problem to delete the calendar/caldav account for me...