Saturday, July 23, 2016


I don't often relax, but when I do, it has to be muddy. Wet. And underground.

I had to attend two conferences in Germany in July. While driving on the autobahns is stressful, I also didn't want to enter the airline system again, so I chose to drive from southern Germany to Berlin. The added bonus was that I was able to stop where I wanted. Snow would have been too big of a detour, but there are many caves in Germany, so I decided to look for one. I ended up in the small, sleepy village of Ennepetal, near Cologne.

Ennepetal is the home Kluterthöhle, second largest cave in Germany. This is a 5.5km karst cave. It is also a show cave, with visits arranged both for tourists and those willing to get a bit more dirty and crawl through the passages of the cave. These adventure tours are not demanding, small kids can take them, but they you will be totally wet and covered in clay at the end of it. The 90 minute tour takes you through large and small passages in this mostly clay-covered system.

The organisers told me that I didn't need my rubber boots, but if you rubber boots you will need them. I was able to climb above the water in the passages, but my hiking boots were full of clay afterwards.

Much recommended. The only complaint that I have is that the tours went on a relatively fast pace, and I didn't have much time to take photographs. In fact, I got left behind at one point due to taking photographs, and didn't know what tunnel the rest of the team took going forward. But I eventually found them :-)

The cave's website has their contact information. The adventure tour costs only 8€ and can take everyone from 8 year olds onward. There's also an extreme tour, but that runs very rarely, and is limited to 16 year olds and over.

Photos and videos (c) 2016 by Jari Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.

Thursday, July 7, 2016


I guess we can blame ourselves, as we were looking for the wormhole. We didn't realise the world would change if we went through it. Lost in time for a while, but managed to return back to our universe by going through the wormhole again.

Nokian Pirunpesänkivi (some 30 kilometres from Tampere) is a tafoni, a rock with holes through it as if they were made by worms. It is a wonder of nature that can be visited without any special equipment or knowledge. Just be careful about going through...

See also the articles at Retkipaikka about this and other tafonis in Finland.

Photos and videos (c) 2016 by Jari Arkko and Janne Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.

Monday, June 27, 2016

Water in Boots

Hulubergsgrottan. Sipoo, Finland. Tiny hole, only crawable. And now filled with dirty water. What could be more fun to explore?

Hulubergsgrottan is one of the few karst caves in Finland. It has been formed as part of a chemical process where water dissolves certain types of rock. This cave is just a few meters long, but still offers a nice caving experience given its low ceiling and hidden opening in the thick forest around it.

The cave has two chambers, the first of which is sometimes free of water. But not on our visit; we had to crawl in the water and mud to move around. The cave's ceiling is nice and for-Finland-rare limestone. At the end of the main chamber there is a hole that should continue to the second chamber, but we were unable to enter there with all the water filling the tunnel.

The article in retkipaikka by Antti Huttunen is the best resource for this cave. Antti has also visited the second chamber in the cave. The coordinates of the cave are N 60° 19.406' E 25° 16.633'. The cave is protected; treat it with care.

Photos and videos (c) 2016 by Jari Arkko and Janne Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.

Friday, June 10, 2016

Cave Surveying Course

We often have just coordinates. While Finnish caves are small, they are often also non-obvious, mere collections of holes under boulders. Would be nice to have a map, to even know if we're in the right hole.

Enter the cave surveying course by the Finnish Caving Association.

Last weekend Janne and I joined a group of other enthusiasts on Luolaseura's course, with Johannes Lundberg from the Swedish Caving Association instructing us. The course started with an introduction to cave surveying and drawing maps, then we went to Lohja's Torhola cave.

We used old-school measuring tape, compass, and inclinometers, but also state of the art laser measurement tools with community-provided extensions. Quite some extensions, in fact, such as installing new motherboards and adding compasses, making the device more suited to caving.

We learned the basics of surveying a cave, measuring its size, position, form, and features. We also learned how to draw maps. This is very difficult!  I ended up making a few different ones, the vertical maps being perhaps the easiest to make. Below you'll find one example, inspired by the various different parts of the cave -- such as one with the tourists or the one where the local youngsters organised a party at 3AM, waking up one of the participants who was sleeping in a tent nearby.

Overall, a very useful course! We also identified a need to develop survey and map techniques for the boulder caves. These types of caves are rare, mostly appearing just in the nordic countries. There seems to be no easy way to draw understandable maps of these caves, and all cave surveying experience has been focused karst caves that typically have a more well-defined form.

I was also surprised to learn that there is no good home in the Internet for cave maps. This seems like an obviously useful thing to have, hopefully that could be started by somebody.

It was also fun to see how natural Janne is at caving. At age 13, he is obviously still not as big as us grownups, so he can enter places we cannot. But he also seems to have a natural ability to twist himself in the right way to fit into tight places. This was useful when we tried to explore the lower "exit" of the Torhola cave. The exit is blocked by a stone, but you can enter a small tunnel leading to the stone, and at least be able to talk to the other cavers inside the bottom of the cave's "basement" part.

Many thanks to the active caving society, the course participants and Johannes!

Photos and videos (c) Jari Arkko and Janne Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.

Sunday, May 29, 2016

Bruxelles Ski de Plastique

Brussels has run out. They do not have enough for themselves, let alone for Greece. The Eurocrisis is getting worse. We're out of snow.

Well, there's really no snow in Brusseles, but fortunately they have come up with ways to deal with this difficult situation. Some years ago I found indoor ski slopes from Peer and Comines villages.

I am proud of my ability to find potential ski places. But I was blissfully unaware of a great slope not too far from the centre of Brussels. My friend and avid skier Catharina (CC) moved to Brussels some time ago, and found Yeti Ski. Interestingly, none of the locals that I asked about this had ever heard of the place. Yeti Ski resides in Anderlecht, near other sports venues and ten kilometres from the centre.

A networking conference took me to Brussels for a couple of days in April. This allowed us to go explore this plastic hill on one of the evenings, after the conference.

The hill is kept wet by sprinklers placed every few meters across the whole slope. Skiing wet plastic is surprisingly challenging. Both of us were recovering, I was trying to heal my broken ribs and CC was dealing with a flu. We skied only a couple of runs, but it was clear that practicing on this hill would improve anyone's skiing skills.

One difference to real snow is that it is much more difficult for your skis to get a grip on the plastic. Braking and turning needs to be done much more aggressively.

I can recommend a visit here, if you are in Brussels! You should take some protective clothing with you, i.e., long pants, long sleeves, and gloves. Falling on the plastic can hurt you otherwise.

Photos and videos (c) 2016 by Jari Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.

Snowing in May @ The Beast

The morning was warm and sunny both in Canada and US, as it should be in mid-May. Ted was planning to have a sunshine-filled ski day. But by the time we reached Killington, it was snowing.  Winter conditions!

Fortunately, I had a extra jacket in my luggage, problem solved. But, it didn't help much with the skiing. I hadn't skied properly in two months, and Ted hadn't had much skiing this year either. At this time of the year, Killington's Superstar is the only open lift and ski run, but it is a demanding, steep moguls run. On the previous weekend, the easier Skye Hawk run still had snow, and would offer a welcome break from skiing the bumps all day.

The snow on Skye Hawk had mostly disappeared during the week. But today's snowing was covering the grass with a dusting of snow, so I decided to take my chance and try skiing it. I was able to ski it almost to the end, though at few points I had to step with my skis to avoid damaging them on rocks.

It is a rare opportunity to ski in these conditions in May. And Killington is one of the only two open ski areas in eastern North America. They are open for an amazingly long time, given that it has been a bad snow year. The trick is of course snowmaking. Superstar still had as much as ten meters of snow in the middle of the run.

And it was a rare opportunity to ski with Ted as well. We've known each other for 10+ years, worked in the same team, saw each other in conferences, and always talked about going skiing together. But somehow it never turned into reality until now. Very happy that we got to do that now! I am on a long business trip in the US, wanted to keep weekends free instead of working through them, and the few ski areas still open made it possible for both of us to drive to the same one.

I also got to stay at Ted's and Andreas wonderful, hi-tech and energy-efficient, passive home in Brattleboro. Thank you!

On the way back to Boston for my meetings, I also stopped in the New Hampshire ski area, Granite Gorge. It had no snow left, but seemed like a friendly local ski hill, including the Volkswagen Kleinbus sporting Bernie stickers and the "Live free. Shred hard." slogan.

Volkswagen Kleinbus at Granite Gorge:

A traditional American hotel room, perhaps, in Cambridge, Massachusetts:

Ted and me on the lift at Killington:

Top of Killington:

The closed run, Skye Hawk:

Snowing at the parking lot:

Snow covered areas that had been previously all clear:

Google Maps knew that on May 16, Granite Gorge would not be open :-) :

Photos and videos (c) 2016 by Jari Arkko and Ted Lemon. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi.

Sunday, May 1, 2016


Wappu, or first of May is a huge celebration in Finland, traditionally celebrated by hiking to a hill and drinking alcohol. This is very different from other festivities in Finland, where the part about the hill is omitted.

The hill that people traditionally climb is one of the park hills in Helsinki, but this year Janne and I decided to go searching for caves and holes in Espoo. We found the Saunalahti hole, a crystal opening where the crystals have long since departed, just the surrounding granite remains.

We also searched for caves from a large boulder in Suomenoja, and found some small holes under this 5x5x5 cube-formed rock. But what was more interesting was the bouldering routes along the sides. Janne didn't have climbing shoes to try them properly, but it seemed that a few moves could also be made with slippery rubber boots.

Finally, I skied the traditional May run in the Grani ski hill in Kauniainen, my home town. I almost didn't make it, having to leave for a business trip and being late with packing, but in the end I found the half an hour to visit and make a fun ski run in the blazing sunshine, wearing a t-shirt and wondering why the ski area has closed when there's so much snow left.

Photos and videos (c) 2016 Jari Arkko. This blog is also available at TGR. Tämä blogi löytyy myös suomeksi Relaasta.