They're held "in trust" by a fictional entity called the sovereign(ty) or summit.
Avoids any awkwardness with tax. Typical royal get out clause to keep the rich rich.
But the trustees of your estate would have to maintain all of your property in its current condition in perpetuity, and your descendents would not be able to sell the assets off and realise their value without being stung for Capital Gains Tax at the time of the sale.