The Amazonian region of Brazil encompassing the states of Amazonas and Pará is twelve times the size of Italy and accounts for 42% of the country's total area. The state of Amazonas is almost five times larger than the unified Germany. The region preserves the largest continuous area of tropical forest in the world. It comprises one-tenth of the planet's entire plant and animal species, produces one-fifth of the world's oxygen and its river system contains one-fifth of the fresh water on earth. The forest still keeps many of its secrets: To this day major tributaries of the River Amazonas are unexplored.

Scientists claim the existence of approximately 50,000 plant species in the Amazon, of which only 30,000 have already been classified. Furthermore it is estimated that Amazonian rivers are home to some 2,500 fish species. At least 550 species of mammals live in the Amazon region, of which more than 60 are exclusive to the region. Approxiamtely 5,000 of the 20,000 butterfly species identified on the planet are native to the region and there are 950 bird species that make Amazonia into the richest bird sanctuary in the world.

The last thing one might expect in the middle of the Amazon jungle, 1,600 kilometres (1,000 miles) from the sea, is a thriving modern port city: The city of Manaus lies 3º south of the equator, on the northern bank of the River Negro.

Where conquistadors once searched in vain for gold, Brazilians found a modern El Dorado of hevea brasiliensis (the rubber tree), a natural commodity of the American tropics. In 1842 Charles Goodyear developed the vulcanisation process which made natural rubber durable, and in 1890 John Dunlop patented pneumatic rubber tyres. With the expansion of the fledgling automobile industry in the recently industrialised USA and Europe, the price of rubber on international markets skyrocketed. Pioneers flooded into the jungle, creating the boom town of fast fortunes and grand gestures. Thousands of rubber tappers collected the milky juice (latex) from isolated trees found deep in the jungle. The plantation owners, the rubber barons and the bankers prospered and built palaces with their wealth. The "nouveaux riches" quaffed in champagne, lit their cigars with $100 bills, had their shirts sent to London to be laundered, while ladies sported the latest French fashion. Manaus became Brazil's second city after Rio de Janeiro to get electricity and for a brief, dazzling period, Manaus was the richest city in the world.

Rubber production reached its peak in 1912, when 42,000 tonnes of latex were exported. The great rubber boom ended almost as quickly as it began: The evildoer was an English botanist named Alexander Wickham. Tradition has it that this British gent smuggled some 70,000 seeds of hevea brasiliensis out of the country saying they were for Queen Victoria's Kew Gardens in England, and soon plantations in the British colonies in South-East Asia where producing rubber more cheaply than Brazil.

The most famous and bizarre reminder of the great rubber boom is the grand opera house, the Teatro Amazonas. Materials for this temple of art in the jungle were wholly imported from Europe: white marble from Italy, iron pillars from England, polished wood from France. The theatre has 198 chandeliers, including 32 of Murano glass. The dome was originally faced with 36,000 tiles imported from Germany at the beginning of the 20th century. It was completed in 1896 following 17 years of construction and in its heyday, it attracted such great singers as the world-famous tenor Enrico Caruso. Today, fully restored, it can still pull in international names.

Not to be missed are further the British Customs House that was imported from Great Britain in prefabricated blocks and the Floating Docks. Because of their ability to rise and fall as the water level of the river changed with the seasons, they were then considered a technical marvel.

About 15 kilometres from Manaus the yellow-brown waters of the River Solimões meet the inky-black Rio Negro at an 8-kilometre (5-mile) wide junction to from the River Amazonas. The two vast currents run together, side by side without mingling their differently-coloured waters. The Amazon river carries more water than any other river in the world. At some points, the river is 120 metres deep, which corresponds to a 40-story tall building.

Nothing matches the romance of taking a slow boat down the world's greatest river. The gigantic scale of this mighty tropical waterway, its luxuriant vegetation and the conditions of life along its banks have always grabbed the imagination of novelists, screenwriters and adventure seekers. Head deeper into the jungle, experience the rainforest wonders and … stop: Within the depths of the forest a universal silence appears to reign and everything seems to pray for nature.