The Alcazar d'Été was a Café-concert which opened in 1869, at 8 Avenue Gabriel in Paris, and closed in 1914.
The old Café Morel behind the Élysée Palace was acquired in 1869 by Arsène Goubert who at the time was owner of the "Alcazar" at 10 Rue du Faubourg Poissonière. He gave it the name "Alcazar d'Été", and the "Alcazar" became "Alcazar d'Hiver". It is today the "Pavilion Gabriel".
François Caradec & Alan Weill, Le Café-Concert, Fayard, 2007 (in French)