Objects important to the main characters?

The Bastille, a prison in Paris, is important to King Philippe because his twin brother is imprisoned there.

The Chateau de Vaux-le-Vicomte, a palace in France, is important because it is the place where King Louis XIV is kidnapped, allowing Phillippe to take the throne.

The "sun" is an important object and symbol of King Louis and his monarchy.

Fouquet's horse is white.... a symbol of his innocence.

The mask is a symbol of imprisonment and anonymity. Its wearer cannot be identitifed, and if things go the way they've planned.... he never existed.