Housed in the fish market in the city of Trieste, the Aquarium is an attraction even just as a building, with its bell tower and Art Nouveau style that stand out on the embankments of the city. Inside is one of the oldest aquariums in the world (dating back to 1933, set up by adopting the derivation from the Latin word aquarium and therefore without the c) dedicated to enhance knowledge of the fish and crustaceans typical of the Adriatic in their environment, although there is also a coral reef tank.

Even the technical facilities still reflect the original design and the water is taken directly from the sea at the base of the pier and pushed to a height of 20 m in the clock tower. The water is subjected to mild filtering, which allows the plankton and other nutrients to reach the tanks which become a splinter of the Gulf, where the different species can find the trace elements they need. This also helps to support births of algae and marine animals inside the aquariums, brought by the water in the tanks in the form of spores, eggs or larvae.

For the same reason the periodic and natural turbidity of the sea, passing through the tanks, sometimes makes the water less clear than usual. The unique architecture of the historic building makes it impossible to set up large tanks but means that for the most part the historical arrangement is still present. Trieste Civic Marine Aquarium makes it possible to observe and learn about local marine wildlife in the live state, whereas all too often it is encountered only in menus or on the counters of the fishmongers. Thanks to the commitment and cooperation of the fishermen, some fish are saved from the nets and accommodated in display tanks.

After careful treatment by the attending veterinarian, many animals still carry clear signs of their encounter with hooks or fishing lines.However, to watch them dart around the tanks is to admire the peculiarities of their striking ecology, raising awareness of sustainable fishery, biodiversity management and respect for the marine world. Upstairs there is an unusual reptile house that is home to amphibians, lizards and in particular snakes, both local (it includes all the poisonous snakes that can be found in this part of Europe) and exotic (including an albino python of over 4 metres). These exotic species have been found abandoned near the city. Thanks to a partnership with the Museum of Natural History in Trieste, finally, the Aquarium hosts 2 very particular collections: a review of kitsch in the collection of shells, which is arranged around the Rossovich Silver Fish: a nineteenth-century collection, unique in the world, of Mediterranean fauna photographed with the technique of metal electroplating.