This is the Müller’sches Volksbad in Munich, a historic Art Nouveau indoor swimming pool located right by the Isar River.
Opened in 1901 and inspired by Roman thermal baths, the building is considered one of the most beautiful indoor pools in Europe.
The facility is situated in the Au-Haidhausen district, near the Ludwigsbrücke bridge and the Deutsches Museum.

*** Best viewed at original size ***