Hey, Thoiry houses a magical show! Each solstice, the sun rises and goes down exactly in the axis of the great vestibule on the castle’s ground floor. So it’s like a huge fire in the interior! It looks like the sun rising in Montségur castle, do you remember?
We see the sun one entire week before and after the solstice in summer, and 15 days in winter. In fact, Thoiry is like a giant calendar: the castle is the pivot, the horizon is the dial, lines created by the perspectives are hands.
French architect Philibert de l’Orme (a big name from the Renaissance era) raised Thoiry in 1559 based on the Golden section. Egyptian pyramids, the Parthenon, every Antic monuments were raised based on this harmony and universal perfection rule. It’s the perfect proportion.
With it, they could get the pure beauty... this is to say just over 1,6! The «divine proportion»... There you go! Thoiry vestibule has the same proportions as the funerary room of Cheops pyramid.
But the castle was raised for a chap fond of alchemy, Raoul Moreau. An inquiring dabbler, king Henri II’s Lord High Treasurer, who put up here the place where he made his alchemical researches.