There’s something about holes. They’re real – everyone knows that. And yet, they’re not really real. A hole is really just the absence of the real stuff that surrounds it. It’s as real as a shadow. In fact, a shadow is a hole; a light-hole. I’m thinking about holes because the day after tomorrow I plan on walking with an organised group to a hole (I hope) in a mountain above a town in the Pyrenees.

There are holes and then there are holes. Holologists generally recognise 3 types. Type 1 holes are complete holes – the true holes; a tunnel with two ends right through something. A hole in my sock is a type 1 hole, so is a train tunnel. Type 2 holes are not really holes at all – they are just hollows. Dig a hole in my garden and you have made a type 2 hole. Caves are usually this type too. Type 3 holes are illusions that look like holes. A coiled spring looks like a hole when viewed end-on but is revealed to be not a hole at all when viewed side-on. On my walk I hope to find out whether the hole is type 1 or type 3 – the real thing or just an illusion. It can’t be type 2 because I saw daylight.

Three years ago, while driving near Maury towards Perpignan, I glanced up at the jagged mountain ridge and was astonished to see what appeared to be a patch of bright sky through a hole in the mountain ridge. A hole – incroyable! My car passengers were asleep so I couldn’t easily check with them, there was nowhere to pull over, then the road quickly took us out of sight of the apparent hole. I made a mental note to Google it later – locals must know about this unusual rock formation and someone will have described it on the Internet. Wrong. Without knowing the name of the exact place, I was unable to find any mention of it. I resorted to Google street view, virtually driving back and forth over kilometres of the D117 but failing to spot the hole.

And now, Jen tells me the local walking group is going up in the hills above Maury to a rock formation called L’Arche Perdue. Would I like to go? Would I ever!

L’ Arche Perdue. The name doesn’t definitively tell me whether it’s really a hole or just an overhang of rock that, viewed from a certain angle, looks like a proper hole. Whichever, it tempts me. I will resist Googling that name; I want to discover it, be amazed by it, ponder its provenance, then, and only then, read the official version.

For now, I am pondering what might cause a large hole in a mountain. People? The Cathar castles along those ridges are spectacular constructions. The people who made those castles would certainly have been capable of creating a ridge-top hole. But I think that unlikely – the hole looked natural to me. And why would anyone make such a hole anyway? I suppose a natural process is more likely. My hope is a spectacular and sudden event – perhaps a meteor striking at a low angle, blasting right through the sharp mountain ridge. Wouldn’t that be something! I admit that seems extremely unlikely, though. A tor part-fallen and left leaning against a nearby cliff? That seems more likely. Could any gradual process of wind or water bore a hole like that? I can’t quite see how.

I promise to post pictures and explanation after the walk.