Whenever there are discussions on this forum about aquariums, most of the top contenders are only marine (seawater) or with very limited freshwater exhibits. This is perhaps understandable because sharks and coral reefs are big draws for aquariuams, but a bit unfortunate since almost half the worlds fish are from freshwater. What are the best and most complete freshwater aquariums? It is irrelevant if they have marine exhibits or not and the same is the case for land-only exhibits that could belong in a normal zoo. To limit it, I have found four requirements to be on the list. I realize that there are many aquariums that only fail in 1-2 of the requirements and that is the very idea of having them: * General good exhibits. * Good collections of both large (at least 60 cm or 2 ft) and small (smaller than 30 cm or 1 ft) fish. * At least one aquatic vertebrate that isn't a fish (e.g. turtle, crocodile, newt, river otter). * Good collection of species from all five main freshwater ecoregions of the world: 1. North Hemisphere Temperate (North America+Europe+North Asia); 2. Neotropics (Central America+South America); 3. Africa; 4. Southern Asia; 5. Oceania (Australia+New Guinea). Examples could be: 1. Mississippi or European Lake (e.g. sturgeon, trout, shiner, pond slider); 2. Amazon Basin (e.g. Neon tetra, arapaima, piranha, caiman lizard); 3. Lake Malawi or Congo River (e.g. Malawi/Tanganyika cichlid, bichir, elephantfish, dwarf crocodile); 4. Mekong River or Western Ghats (e.g. gourami, loach, snakehead, small-clawed otter); 5. Murray River or New Guinea Rivers (e.g. rainbowfish, Australian lungfish, pig-nosed turtle). Three aquariums that comply with the requirements are: Berlin Zoo Aquarium Chicago Shedd Aquarium Tennessee Aquarium What other aquariums belong on the list?