All the king’s … swans? A quiz on the British royals’ assets.

When thinking about British royal wealth, the first thing that comes to mind might be all the palaces and jewel-laden crowns. But you may find it surprising to learn that many of the country’s sea creatures, bodies of water and vast tracts of tax-free land are also royal.

How much do you know about the properties and other assets owned by the king, the royal family or the Crown?

As monarch, Charles also benefits from the Crown Estate, a collection of land and asset holdings originating from the Norman Conquest in the 11th century. It’s an independently run company, and its profits go to the state treasury. But the royals benefit from those profits.

Besides the property of the Crown Estate, royals also profit from the Duchy of Lancaster and the Duchy of Cornwall, ancient empires that generate income for the monarch and their eldest male heir, respectively — in this case, Charles and Prince William.

The heirs can’t sell core duchy properties. But they are entitled to the profits from leasing rights and investments. Charles, for example, received an annual payment of more than 20 million pounds ($25 million) in recent years. Royal duchies, unlike other businesses and landed estates in Britain, are exempt from corporate and capital gains taxes, though Charles voluntarily paid income tax.

Hundreds of thousands of items make up the Royal Collection, one of the largest art collections in the world. Though it is not personally owned by the monarch, it is held in trust by the king as sovereign.

From the streets of London

The Washington Post asked similar questions to residents of London to find out how much locals know about the property and other assets owned by royals. See how you did compared with them.