The closest you’ll get to scuba diving without a wetsuit, Oceanário is mind-blowing. With 8000 marine creatures splashing in 7 million litres of seawater, no amount of hyperbole does it justice. Huge wrap-around tanks make you feel as if you're underwater, as you eyeball zebra sharks, honeycombed rays, gliding mantas and schools of neon fish.
Keep an eye out for oddities such as filigree sea dragons, big ocean sunfish, Portuguese sardines, otherworldly jellyfish, frolicsome sea otters and squiggly garden eels. You’ll also want to see the recreated rainforest, Indo-Pacific coral reef and Magellan penguins on ice. In light of the 2013 documentary Blackfish, entertainment aquariums have fallen out of favour, but for what it's worth, this conservation-oriented oceanarium offers no entertainment shows, it reproduces, as opposed to capturing, in the wild wherever possible, and runs the largest environmental education program in Portugal. It was also building a more sustainable restaurant and cafe at the time of research.