Neuschwanstein Castle, Balmoral Castle, Himeji Castle, and the Alhambra.
One of the strangest loopholes in the tax code, one that still exists after the recent TCJA changes, is the home rental provision. If you have a primary residence (or in some cases a secondary residence) that you rent out for a period no greater than 14 days in a year, all the rental money is tax free.
Definitely check with an accountant before doing this, because you don’t want to miss ticking off any of the boxes, and realize that this loophole is strict: one day over and the whole thing becomes taxable.
On the other hand, the amount of money you make is irrelevant. If you lived in an exact replica of Neuschwanstein Castle in Bavaria, Balmoral Castle in Aberdeenshire, Himeji Castle in Hyogo Prefecture or the Alhambra in Andalusia, and someone offers you $400,000,000 for a twelve night stay, all of that money is tax free.
Now, will someone offer you that kind of money for your middle class house in Albuquerque? Probably not, but if some crazy billionaire does, definitely take them up on it.