I've not drained very extensively, but a few days ago I found a ~500 foot straight drain under an overpass with google earth; most here are just drainage canals leading under roads, and this is a big contrast (alongside a more "real" locked entrance I found in a treeline.) For you, when does a drain cease to become a little tunnel and turn into something really interesting? (I'll actually go with anything I can stand fully erect in...)

Posted by [Olive] fully erect

Aaand there's your answer.

What you're describing is a culvert, right? I've taken decent pictures using very unimpressive culverts before, so if that's your interest, it's worth it. However, it's not quite like bringing a dozen people and fireworks on a 1.5-kilometer underground voyage.

Maybe an easy rule of thumb, not that one is that badly needed, is it becomes a "real" experience when you're far enough underground that you can't see sunlight coming in from the entrance behind you.

If it's exciting enough to make me enter and fun enough to not turn me back almost immediately, I count it.

well we got some guy on here who explored a crop circle

it was real I guess...

Posted by [Olive] I've not drained very extensively, but a few days ago I found a ~500 foot straight drain under an overpass with google earth; most here are just drainage canals leading under roads, and this is a big contrast (alongside a more "real" locked entrance I found in a treeline.) For you, when does a drain cease to become a little tunnel and turn into something really interesting? (I'll actually go with anything I can stand fully erect in...)

Meh, pics or it never happen (the standard UER disclaimer/fallback line)

Posted by Steed Maybe an easy rule of thumb, not that one is that badly needed, is it becomes a "real" experience when you're far enough underground that you can't see sunlight coming in from the entrance behind you.

Gold standard.

That actually makes me pretty optimistic - thanks guys!

And I now know what a culvert is

Posted by The Juge If it's exciting enough to make me enter and fun enough to not turn me back almost immediately, I count it.

Pretty much this. If you felt it compelling enough to leave the beaten path and check it out, then I'd say that's an experience. Of course some experiences are more interesting than others, but the things you explore need not all be huge and epic.

There is no set of standards for exploring. It is whatever you make it. Don't worry so much about what other people think. If you found it to be interesting, that is all that should matter

Posted by [Olive] when does a drain cease to become a little tunnel and turn into something really interesting?

When you find the big tunnels.

Or when there's an unanticipated flash flood...

When is it real? The moment it's real to you. Don't let someone else set your parameters for enjoyment, not in this hobby above all others. My $.02

Posted by Jonsered When is it real? The moment it's real to you. Don't let someone else set your parameters for enjoyment, not in this hobby above all others. My $.02

I agree with this.

I can also remember being a new explorer, and seeing all the amazing photos online and comparing my own experiences to what I saw online. If you gauge your experiences that way, you'll be continually disappointed, because someone, somewhere will always post something even more awesome!

Cement drains with burners from the best local artists are always fun.