Think I'd have to agree with
Pom Pax on that. Here's a couple of examples to look at...
Blowing off some steam and
the end of a blow. Both photos depict Mount Tavurvur, which is basically nothing more than a steam hole on the side of a massive caldera. The caldera opened to the sea at some stage in pre-history, allowing the formation of what is now known as Blanche Bay or Rabaul Harbour, or...
Anyway, the whole Rabaul township and docks sits right on the bay and, therefore right on the lip of this ancient caldera. About the only thing different is that, after take-off, it's not necessary to orbit up over the town/airport before setting course.
All the instrument approaches to the new Rabaul airport (Tokua) warn of active volcanoes in close proximity. That makes it real nice
when you can't see where you're going...
And, yeah, before anyone else pipes up, I'm the bloke who put those warnings on the charts.