Cash only places/attractions in the Jungfrau area?

During my forum 'travels' I have read of a few places that only take cash - but foolishly didn't take note of them!

Can anyone please tell me of any places/attractions/situations (in the Jungfrau/BO area) where I would be unable to pay by card? I don't want to be stuck on a mountain without enough cash (for 5 of us) nor indeed to carry too much cash without reason.

Depends on what you mean by "stuck on a mountain"

The busier tourist areas up in the mountains such as Schilthorn and Jungfraujoch certainly take plastic. As do the feeder regions: Kleine Scheidegg, M​ürren, Wengen, Grindelwald, etc.

If you are planning to do some high mountain hiking and ending up at huts/berghauses/etc there will be no plastic possible there.

If you could let us know where you are planning on going we can be more precise.