Vertigo: Richard Peduzzi at Orsay

At the far end of Orsay's great nave, the Opéra Garnier is sliced open lengthwise: a 1/25 scale section almost 5.80 metres long, made from a drawing by Charles Garnier. Beside it, a 6.50-metre model lays out the Opéra quarter as it stood in 1914, and you look down on it from above.

Both have stood there since the museum opened in 1986, arranged by the stage designer Richard Peduzzi, Patrice Chéreau's longtime collaborator. For Orsay's 40th birthday his own paintings, drawings, sculptures and set models now surround them, including those for Chéreau's Lulu at the Paris Opera in 1979. The endless walls, towers and ruins of his sets hang beside drawings he chose from the museum's collection.

If you already know the models, the new part is the theatre work around them. The extra hang leaves in January; the models stay. It's covered by the €16 timed museum ticket (€12 on Thursday evenings, open to 9:45pm; free for under-18s and EEA residents under 26).