Question: Who was the architect of the opera house where Thaïs was first performed?
Sentence (from "Palais Garnier"): It was called the Salle des Capucines, because of its location on the Boulevard des Capucines in the 9th arrondissement of Paris, but soon became known as the Palais Garnier, in recognition of its opulence and its architect, Charles Garnier.
Relevant evidence: Yes