[Dakuten]

I'm somewhat stumped on this one. I was thinking of torii-style gates, and they don't quite fit into a nice category. My first thought was to use 軒 (ken), but a gate isn't a building. 口 (kuchi) doesn't seem to fit; even though it means 'entrance', I don't think it's ever used for counting entrances. My third thought was just to use ヶ (ko), but my impression is that you don't use ヶ unless there is no other counter to use (which I don't think would be a common occurrence considering the number of counters there are).

So, which josûshi goes with "門"?