As part of our week-long series about how the arts are dealing with Covid-19, we take you to some of the precious heritage sites that are fighting for survival. Eve Jackson reports from one of Europe's greatest stately homes, the Domaine of Chantilly. An hour away from Paris, it's France's largest privately owned estate. It includes a park, a Renaissance chateau, a racecourse and the biggest classical art collection in the country outside the Louvre.