Margen
On the island of Yap, in Micronesia, traditional money takes the form of rai: limestone discs with a hole in the middle that can measure over three metres across and weigh some four tons. The stone doesn't exist on Yap: it had to be quarried in Palau, about 400 kilometres away across open sea, and brought back by canoe. That journey, and its risks, was precisely what gave each stone its value.
Since moving them was madness, nobody moved them. To pay, it was enough for the whole village to know the stone had changed owners. The disc stayed exactly where it was.
The ultimate proof: over a century ago, a rai sank at sea during transport. The community decided the stone still existed and still counted, and it kept changing hands — at the bottom of the ocean. Your bank balance works exactly the same way: nothing moves, only the record changes.