What is today San Sebastián's City Hall was home to the city’s Gran Casino from the time it was opened on 1st July 1897 until it was closed in 1924 with the prohibition of gambling. Its roulette tables and Dance Hall, currently the Plenary Hall, provided entertainment for politicians, writers and artists in the Belle Epoque period.
https://www.sansebastianturismo.com/en/to-do/culture-art-architecture/belle-epoque#ayuntamiento