Is cave exploration an indoor or an outdoor activity?
You’re indoors in the sense that you’re protected from the weather and the elements, and the cave could even have some kind of covering or entrance area that could be considered a door or doorway. People have built homes in caves.
Some people live in huts or other types of human dwellings that don’t have entry doors. They have doorways.
When I was visiting the Philippines I saw homes on stilts that did not actually have doors, but I would certainly consider the inside of such a structure to be indoors. Pre-colonial architecture may not use a front door.
I recognize this isn’t a great argument, but it’s arguable I think in principle.
If you go in the door you’re indoors but if you don’t you’re outdoor.
This could lead to a strange situation where you enter the cave through a doorless entrance and leave through an entrance with a door, making the outdoors indoors in the split second before you fade from existence.
I say outdoors. Indoors has a vibe of being human made to me, and a low likelihood of encountering wildlife. So I guess walking around a mine is indoor cave exploration
Many caves are modified to accommodate their visitors. This could be a small as leaving behind oxygen tanks or equipment, or as advanced as installing electrical wiring and ventilation. This was the case of several caves I visited as a tourist with no real exploration skills.
Now that's a good question.
I believe it's still outdoors, indoors has the meaning of "comfort from your own home" rather than meaning inside a closed off area. Knitting is an indoor activity, hiking is outdoors
I would consider a cave to be "outdoors" unless maybe somethings been done to it to make it into a dwelling. Since there is no door it's at least somewhat open to the elements, you would have to contend with various wildlife that may live there, the floor would be either dirt or bare rock, these are all things one would have to deal with while doing "outdoor activities"
The "door" part doesn't really have any significance. No one would say camping under the open sky is an indoor activity, even if there's a fence with a door around the campsite.
I think it makes more sense for the deciding factor be whether you're in a controlled or uncontrolled environment. And while part of the cave might be controlled if there's an artificial entryway or home, that's not what you're there to see.
I’ve been in show caves in Bonaire that had some degree of climate control, mainly for humidity and to ensure sufficient oxygen for visitors for a comfortable experience and to accommodate large groups.
Certainly that’s the exception rather than the rule in my case.
I agree with the door argument but would also add my two cents... If it's a cave dwelling it would be inside but you also wouldn't be cave exploring. You'd be in a 'civilized' area