Just back on Sunday and did the Tunnel Saturday midday after a small snowfall Friday evening.
Looking at other posts on here and some photos and videos, it is impossible to say what this run is like as it is totally and utterly dependent on conditions how you find it.
Andy Hull posts photos with fantastic thick soft snow on this run, and says how it widens out into a lovely run. That is nothing at all like my experience, and his photo from the top prove why....no moguls, just fresh snow. I would pay someone to ski it like that!!!
The last video above is much more like how I found it, and also speaking to others in resort this is the regular kind of conditions you find it in.
I have to say its one of those runs, like the Hari Kari in
Mayrhofen, that has a reputation and scares people off. I've done both, and I'd ski the Hari Kari with my eyes shut after doing the tunnel.
The top section is steep. It had no route into it when I did it, you just have to pop over the edge and try to plan a route, but the moguls were approx 4 feet high with just skied out turns between them, making it impossible for anyone other than total expert or ski instructor standard to get any momentum. I spent the first 5 minutes working my way down off the top, planning the next couple of turns, not finding them and then stopping to replan! Mentally, this is tougher than it is physically!
However, once the first mogul section has been conquered, there is a part where the angle of the slope subsides and you can open up into what I would basically call off piste territory for a while.
However, you are then met (if you take the left hand route down to the Lac) with another stupidly steep mogul section, even harder than the top because its much narrower and the moguls here were rock hard. I am sure in different conditions it all seems totally different to ski.
I managed to get down it with only one incident, a massive wipe out when I got into a rhythm on an open section, following a group of French freestylers, but turned straight onto a rock which was covered in snow and created a huge jump.....I was in mid air for a couple of seconds before coming down into reasonably soft snow and going over! Goggles, hat, a pole and 1 ski had all departed!!!!! Fortunately, I am fit and experienced enough to be able to recover, put the ski back on, and carry on the run without any bangs. However for a minute it was a bit frightening, mainly because I had skied it alone, following the group on my way down for comfort. Mrs H just didnt fancy it at all, she said she felt sick looking at it from the Pic Blanc cable car, and my ski buddy and his wife who came with us were too tired to consider it.
As a fairly decent intermediate skier, in my opinion, I would say to anyone considering the Tunnel that it is more certainly not to be taken lightly. It is a very difficult run, I dont care what anyone says, there are signs before you enter it warning you it is VERY difficult and they are right. However, get a dump of snow and a bluebird day and I am sure it would be fabulous to ski, albeit still very technically hard.
Its one I can now say I've done, and delighted to have got to the bottom without major incident. A covering of snow on my bobble proved my fall!
Very good skiers will tell you anything is possible, but this run has so many variants that you simply cannot just get on with it and ski it. Its a challenge, a test, a quiz, and you really do have to respect the mountain up there.
Great sense of achievement when I hit the bottom run into the
Lac Blanc chair lift however.
i tried to get some photos on the way down but I only had my iPhone and its hard to reflect how this run really comes across:
The entrance which some people actually find intimidating!
First part off the top, my stupid finger over the lens as I was trying hard not to drop the phone!
Decent view part way down, you can see 1/5 of France on a clear day

This photo really does not do justice to the severity of the slope in terms of gradient here. The rocks where the left hand boarder is were about a 25 metre drop with an angle of about 75 degrees, next to the moguls. And yes, the boarder did make the jump off the rocks!!!!