Getting to the Oceanario in the Parque das Nacoas, the scene for the World Expo in 1998, is an interesting excursion in and of itself. You take the Red Line Metro to Oriente and then walk through the immense Vasco da Gamma Mall. This mall is the creation of the famed Spanish architect, Santiago Calatrava, and is a cantilevered marvel that looked eerie on a misty, rainy day. As the photos show, the murals in the metro station also underline Portuguese pride in da Gama.

We were jolted with surprise when we exited the Metro and saw throngs of locals shopping away their weekend just like many Americans. It’s a 10-minute walk to the Oceanario right on the waterfront (naturally) and to the northeast of the Mall. The ticket queue was 20-minutes long, filled mostly with Lisboetas and their excited children.

This building of stone and glass is stunning, designed by an American architect, Peter Chermayeff, and compliments the modernity of Calatrava’s metro station.

The huge 13-million-gallon tank is filled with about 25,000 fish and marine animals. This Oceanario is not the world’s largest; apparently, there’s an aquarium in Osaka, Japan that holds that distinction.

But, frankly, it’s astounding, and, on a day when there weren’t the overwhelming crowds we encountered, we would have been able to appreciate more fully the mesmerizing and soothing sight of so many species swimming along before us. Instead, the Oceanario was very hot and crowded. Cries of, "Mira! Mira!," rang out incessantly through the darkness as conscientious parents tried to draw the attention of their young children to the indisputably excellent visions before them. The darkness of the lower viewing levels exacerbated my claustrophobic unease – already high because of crowds and stifling heat! DO NOT GO ON WEEKENDS unless jostling, dense crowds don’t affect you aversely.

I felt much better viewing in the areas exhibiting recreations of the eco-systems of the Atlantic, Antarctic, Pacific, and Indian Oceans. All was not in darkness, but in plentiful light, and with delights such as observing playful otters. Skillful depiction of the flora of the various regions gave you the sense of moving into sharply diverse oceanic atmospheres.

This most memorable remnant of the Expo is a must-see in Lisbon. We just chose a crowded day, unwisely but necessarily - it was our last day in Lisbon.

In addition, our son was just recovering from a flu-like bug he’d picked up, and both my husband and I were coming down with it. After we left this landmark, we strolled around the Parque, for the rain had abated. The sweeping river view and spaciousness of the plazas served as welcome relief. Most cafes were closed, but in nearby Vasco da Gama Mall, there were more than a sufficient number of open eateries.

When I went, some of the pavilions that are going to be used again were not yet ready but there was another large pavilion with information on the world's oceans, a chair lift right along the site and and some good outdoor garden scenery.

How to describe the Oceanarium itself? I'll start by saying that I have since visited what was previously called one of the foremost aquaria (aquariums?) in Europe and, whilst I enjoyed it, it seemed like a museum in comparison.

The easy part is to say that it is very big and round and that it is entered by a high passage which can be accessed by a lift. Basically you walk for a vast distance at different levels, connected by lift or stairs around a massive tank - so massive that you only know by reason, never by sight, that you are seeing the same water. The fish come very close but they also swim far away so that there is an ever-changing piscatorial scene close to you. This is, as it were, on the inside of you. On the outside are largely open areas to give four separate areas recreating the environments of different parts of the world's oceans. These include non-aquatic mammals - though of course it is those that spend a lot of time in the water like otters - as well as seals and penguins.

I assume there are sights of this kind on the other side of the Atlantic but I have never seen anything remotely like it in Europe.