Resumen: The Almuñecar Aquarium is a 3000 m2 underground installation that shows Mediterranean fauna on two levels below the Kuwait Square next to the market and near the City Hall of the andalusian town of Almuñécar (Spain). The Aquarium emerges to the surface by means of its control building, staircase and lift, all arranged around an open courtyard. We designed a textile roof in order to protect this courtyard from direct sunshine and rain. As the only part of the building that shows above is the membrane, it has also been envisaged as an eye catcher in order to attract visitor's attention. Two water ponds reflect the white and lofty membrane set in front of the backdrop of white apartment buildings.