The dome that I noticed was this one, of the Robinson & Cleaver building opposite the City Hall in Belfast. Its domes have sharper points than most around town :)
This photo was taken from the porch at the front of the City Hall, looking past the statue of Queen Victoria. Strangely, the morning I took this was the first time I'd been in the grounds of the City Hall other than at a Christmas market. The building itself has been closed for renovation, and I could hear the sounds of very focussed work from an open window, but I believe the works are coming to an end. I'll need to make the effort to see inside when it reopens.
I've been paying more attention to Belfast above head-height. I think the project to photograph the top halves of buildings around town might be a goer. We'll see.