It seems that the London apartment market is where rich foreigners are storing their money, even with Brexit looming. As many as 41% of the luxury, high-end apartments in the core of London are vacant, and show no record of bills being paid, etc. (AKA - The heat isn't on, so therefore, nobody is living there.)
In Polynesia, there is a culture (the Yap) that use giant, immovable stones, as currency. They are called Rai stones. Ownership of a stone is simply transferred to a new person, to pay a debt.
... the more things change, the more they stay the same...