Did you know that the world should, by rights, be pink when seen from outer space? Or that spider crabs can grow up to four metres in length? Or that flamingos get their colour from the type of food they eat?

Living under the sea was a childhood fantasy for many of us, and has become the subject of vast numbers of songs, including plenty of silly ones. In truth, none of us would feel comfortable locked, sardine-style, inside a yellow submarine with barely space to breathe and no TV, as the Beatles advocated.

However, a brief taste of this fantasy can be enjoyed in Valencia’s Oceanogràfic, at the Ciudad de las Artes y Ciencias, where the seas of the world and the habitats of their native creatures are recreated inside its futuristic domed buildings.

Far from being poles apart, you can travel from the chilly waters of the Arctic to the temperate, turquoise Red Sea with relative ease following the arrows around the centre’s ultra-modern, avant-garde complex, finding sea-life you never knew existed and learning plenty of useless, but fascinating, information about the world that exists below the waves.

The Arctic
The temperature suddenly drops as you step inside the giant igloo and are confronted with walruses and whales swimming around the icebergs below wooden footbridges, and at the bottom of the steps, you can watch the whole scene again under water. Curiously, the walruses repeatedly dive head-first towards the bottom of the recreated sea, landing flat on their faces. There is no explanation given as to why, but plenty of information on placards about the lives and habits of these enormous creatures – such as how an adult male can grow up to 1,500 kilos and 3.2 metres in length. Their skin is between two and four centimetres thick – Mother Nature’s way of protecting them against the drastic winter climates within the Arctic Circle. In February, temperatures can drop to around –50ºC.

Red Sea
An auditorium with room for up to 477 people, talks about this unique strip of water crossed by Moses in biblical times are given against a backdrop of a huge aquarium containing samples of some of the Red Sea’s famous corals. Separating mainland Egypt from the Sinai Peninsula and Saudi Arabia, and surrounded by desert, the incredible diversity of marine life in its depths have long fascinated divers, snorkellers and scientists.

Oceans
Descending into a tunnel to the bottom of a circular building, you will find some of the most spectacular – and terrifying – species that inhabit the planet’s largest expanses of water, creatures from the Canary Islands and all the way to Bermuda. Sand tiger sharks, whose babies eat each other in the womb, stingrays, black jack mackerel and guitar fish swim around and above you as you pass through the tunnel that links both sides of the building, and can even feel the force of waves breaking above your head. You will discover how the Canaries came about – mostly through volcanic eruptions – and read about Christopher Colombus’ discovery of the Americas, a voyage that radically changed the course of history forever for two continents. To satisfy your inner five-year-old you can even crawl into a small aquarium so the rest of your party can take a picture of you walking around the sea bed, dodging the fish. All of this, without even getting wet.

Islands
Back in the open air, you come to a miniature, rocky archipelago designed to be a reproduction of those found in the southernmost parts of South America where native sea-lions swim in waters of three metres in depth and a constant 16-18ºC. You will read about how the men form harems of between 15 or 20 women during the mating season, which is usually in January, and jealously guard and protect them and their young, barely eating or sleeping, until they are weaned after around a year.

Temperate and tropical seas
Covering such diverse corners of the planet as the Californian coastal kelp forests, the Izu Peninsula in Japan, and the coral reefs of the Caribbean and Indo-Pacific oceans, Europe’s longest underwater tunnel gives you a detailed view of an equally disparate selection of sea-creatures - starfish, anemone, leopard sharks, the Japanese three-tailed sacura margaritacea and the giant spider crab, which can reach up to four metres in length. Readers will be more familiar with eels, dorada, borriquete and jurel, all of which are heavily commercialised in Spanish ports. In the tropical section, colourful aquariums house much smaller, but even more fascinating, varieties of fish in flamboyant shades of pink, blue, yellow, red and purple with curiously-shaped fins and tails, which are highly pleasing to the eye and intriguing to watch.

Antarctic
A vast continent with no native inhabitants besides penguins, where winter temperatures can fall to –60ºC, expeditions have been going on since the 18th century to the south pole but its discovery was credited to British-born Robert Scott and his Norwegian companion, Roald Amundsen, on January 17, 1912, just days after they flew the Norwegian flag believing they had failed in their mission.

Since then, the Antarctic has been a source of fascination to hardened explorers and amateur researchers: in 2001, global insurance firm Royal & Sun Alliance sent a team of its staff members to the south pole for a month to carry out experiments and studies.

More recently, the City of Arts and Sciences, where the Oceanogràfic is based, has joined forces with the Spanish armed forces to take on an Antarctic expedition over the rest of this year and 2007. The Spanish-run base, Gabriel de Castilla, on Deception Island, will be home to a brave team of researchers for several months who will bear the chilly climes to study infections and parasites in seals and sea-wolves.

An exhibition of paintings of previous journeys to the south pole are on display, and a recreation of a rocky cliff houses a colony of Humboldt penguins. A protected species, they are under threat of extinction because of the gradual destruction of their habitat by climatic forces, and lack of food.

Mediterranean
Closer to home, you will learn that the much-talked-about posidonia plant got its name from the Greek God Poseidon, who was reputed to be a protector of the sea and life within it. His floral legacy does just that – the posidonia meadows on the bottom of the sea provide a habitat for literally hundreds of sea-creatures and supply them with food and oxygen, whilst helping to keep the water clean. Fish can snuggle down in the dense foliage, which folds over to provide a natural roof over their heads and keep them hidden from their predators.

These days, the posidonia is under constant threat – illegal tipping and contamination, and outlawed drag-net fishing continue to put it in jeopardy and, most contentious of all, so do desalination plants and beach regeneration. Extracting sand from the sea-bed or depositing sand from quarries on the shore, a practise that has become common in the Comunidad Valenciana just before the start of summer and made necessary by coastal erosion caused by over-development, is slowly putting paid to these habitats of marine fauna.

Wetlands
Gain a deeper understanding into the delicate ecosystem of mangrove swamps and the marshes scattered throughout the Comunidad Valenciana. Biologically, these are some of the richest and most productive parts of the planet and home to endangered species of aquatic birds, birds of prey and fish.

Inside a huge, spherical, state-of-the-art display case, a representation of the Albufera nature reserve, a marsh that stretches from Xeraco to Valencia just inland from the coast, houses a vast array of species from egrets to eagles and endangered breeds of fish like the samaruc and the fartet.

Mangrove swamps, explains the information given en route, are found mainly in tropical and subtropical climates with around 70 per cent of coastline in these areas being occupied by a barely-accessible, semi-submerged jungle, natural habitat for tortoises, ibis and perch, as well as the mangrove tree that gives the swamp its name. Tolerating high levels of salt in the water, they find it practically impossible to take root and almost float.

So much sea-life, so little time. A day is barely enough to take it all in and with guided tours, talks, shows and dolphin displays programmed at different times of the year, there is every excuse to come back – and find out for yourself why the world should be pink when seen from outer-space, together with an interesting little story about a haul of trainers washed up on various shores around the world. We wouldn’t want to give too much away – but here’s a clue. You’ll find both in the section on Oceans.

Tips:
* Although based in the same complex as the City of Arts and Sciences and the Hemisfèric, you will need most of the day to see each one. Whilst it is much cheaper to buy a ticket for all three, you will not get the best out of your visit.
* Avoid high-heeled shoes. Walking from aquarium to aquarium, you cross numerous bridges and platforms made of wooden slats sufficiently wide enough for your heel to fall through and either be wrenched off, or leave you trapped and red-faced.
* There is one restaurant in the Oceanogràfic but coffee shops tend to be outdoor bar areas selling burgers and chips. For this reason, and given that a large part if the centre is outside, it is best to go when it is not raining or freezing cold.
* Reasonably-priced parking is available at the centre and driving there is not as complicated as it sounds. Otherwise, buses are available from the airport and station, among other sites.