The Dipòsit de les Aigües was designed in 1874 by architect Josep Fontserè, as a reservoir building to store water for the nearby Parc de la Ciutadella. It now serves as a fully operational library.
If I am not wrong is part of the Pompeu Fabra University in Barcelona. It’s a astonishing building from the interior.
Beautiful. Does it need to be heated in winter?
Amazing adaptive re-use!