Thieves in Switzerland have conquered one of the country’s most challenging protected climbing routes.

They ascended to an altitude of 2,350m and traversed gorges on narrow steel cables – all to rob a collection box.

The box belongs to a local climbing club, which maintains Switzerland’s longest protected climbing route on the Gemmi pass above Leukerbad village.

What has caused the biggest shock is that the donation box is accessible only to the most experienced climbers.

The route, known as a via ferrata, is classed as level 5, the most difficult, and involves serious climbing as well as ascending ladders bolted into the vertical rock face, and traversing gorges on narrow steel cables.

“What kind of people are these?” wrote the climbing club on its Facebook page.

“The climbing club looks after the via ferrata for no salary, we don’t ask for anything, and now someone has stolen the money donated to maintain it.”

Those who discovered the theft believe it was carefully planned well in advance.

The donation box was found smashed open and empty. The thieves were not only good climbers, equipped with all the necessary mountaineering kit, they took the tools with them to break open the donation box “with brute force” the climbing club said.

Astonishingly, it appears they then continued their ascent, with the money, to the top of the Dauberhorn, at 2941 metres.

Trying to find out exactly who committed the crime may be difficult though – the last few days have been perfect climbing weather, and there were many mountaineers enjoying the via ferrata.

The climbing club is not sure exactly how much money was stolen; but club member and mountain guide Richard Werlen told the BBC it was likely to be at least 400-500 Swiss francs (€420-520; $450-560).

Switzerland is still a country where cash is used on a regular basis, and the Swiss are proud of their voluntary work maintaining hiking paths and climbing routes. A donation for such effort is expected, and gladly given, by large parts of the population.

But now organisations like the climbing club may wonder if they need to change the way they seek donations.

The pervasiveness of cash in Switzerland has already led to a spate of robberies of far better protected ATM machines.

Millions of francs have been stolen in the last three years alone, causing the Swiss Federal Police to warn that the regularly filled and often poorly monitored machines are becoming a magnet for thieves from across Europe.

For the moment, the climbing club is hoping that whoever stole the money will suffer from “a guilty conscience”, and quietly return it.

And Richard Werlen has some consolation to report. This morning, a local benefactor sent in 500 francs to replace the stolen donations.