The grand staircase was designed to show off the ladies' dresses to their best.
It's a dramatic entrance made up of more than 9 different marbles and decorative lines on every surface. Above it are balconies which people can stand and watch who's coming and going.
Then you go through the dramatic entrance to the box seats, lined with red velvet 'to flatter and bring out the youth in ladies faces' according to Garnier.
In 1964, the Opera House commission the famous Chagall painting on the ceiling, which was actually the only thing I didn't like in the place. It looked, to me, a bit like a 10 year old had done it with crayons.
Between the acts, the audience could enjoy the salon and some drinks or food. Elaborate tapestries adorn the walls showing what was available.
Then, the piece de la resistance, the grand salon.
This place was built so the women would sit safely in the boxes and the other rooms were for the men only but on the opening night, the Queen of Spain couldn't contain her curiosity and wandered all over the place, making it acceptable for women to mingle with the men for the first time in history.
If you have one day in Paris, go here.