Oceanário de Lisboa

The Oceanário de Lisboa is the city's best family attraction and a genuinely world-class aquarium, the kind that adults leave as delighted as children. It was built on the Tagus waterfront for the 1998 World Exposition, whose theme was the oceans, and it sits on a pier in Parque das Nações, the modern riverside district that grew from the Expo grounds. The design is the clever part. The building is organised around a single huge central tank — several million litres of water representing the open ocean — which you circle on two levels, catching it through great acrylic windows from above and below as sharks, rays, shoals of silvery fish and, if you are lucky, the strange, flattened ocean sunfish drift past. Around it sit four separate habitats representing the coastal waters of different oceans, each with an open-air section above water and an underwater view below: in one, sea otters roll and groom in a rocky North Pacific cove; in another, penguins waddle and dive on a cold Antarctic shore; elsewhere there are tropical reef fish, puffins and seabirds. Beyond the main building, a second wing hosts temporary exhibitions, which change periodically and are often included in a combined ticket. The visit is self-guided and flows well, the signage is good, and the building is fully accessible, which makes it easy with strollers and wheelchairs. Tickets are mid-priced; buy online, and expect weekends, school holidays and rainy days to be busy.

Getting there is straightforward and part of the fun. Take the metro's red line to Oriente, whose soaring white steel-and-glass station by Santiago Calatrava is an attraction in its own right, then walk ten minutes through Parque das Nações to the water. The district is a pleasant contrast to the old city: wide promenades, gardens, public art, the long Vasco da Gama Bridge stretching away across the estuary, and a cable car that runs along the riverfront. If you are coming from the centre by taxi, allow twenty minutes or more depending on traffic.

Inside, take your time with the central tank. The upper level gives you the surface view and the light falling through the water; the lower level is where the big animals pass close to the glass, and there are benches where you can simply sit and watch the ocean go by. The otters are the stars for most children, especially when they are active, and the penguins are good value at any time. Allow around two hours for the main exhibition and add time if the temporary exhibition interests you. There is a café and a restaurant on site, and shops selling ocean-themed gifts; the waterfront outside has plenty of other places to eat.

When to go: weekday mornings are the quietest, and late afternoons can thin out after school groups leave. On rainy days and at weekends, expect lines and crowding around the most popular windows. The Oceanário has a strong education and conservation mission, with information about marine protection throughout, and it is a good place to talk with children about the ocean that shaped Portugal's history. Pair the visit with a ride on the riverside cable car, a walk along the promenade, or a stop at the Vasco da Gama shopping centre by the station if you need supplies.