Lost land of water and rock.

• Author: Malatesta, Parisina
• Position: Venezuela's Gran Sabana

Just south of the Orinoco, Venezuela's ancient Guiana Highlands rise abruptly, extending across half of the country. Centuries of erosion have given rise to plateaus heavily etched by swiftly moving streams and rivers. The country's major waterways--the Orinoco itself, as well as the Caroni, Ventuari, Cura, and Paragua--originate there. In the eastern portion of the Guiana Highlands, some thirteen thousand square miles known as the Gran Sabana, is some of the most remarkable topography in the Americas.

Before the Atlantic separated Africa and South America, before the Andes appeared, and before the Amazon River overflowed its course, a mountain range extended across six present-day countries--from Venezuela through vast parts of Colombia and Brazil, and through all of Guyana, Suriname, and French Guiana. Over thousands of years the mountains eroded, creating layers of sandstone, which became further weathered and fractured, crystallizing into quartz and jasper and forming fantastic windswept columns over three thousand feet tall, called tepuis.

In the Gran Sabana, these extraordinary, flat-topped bluffs connect with undulating savannas and jungle in a mysterious equilibrium of variety and singularity. Under halos of mist and fog, bromeliads, arborescent ferns, and insectivorous plants, their imposing walls emerge, with waterfalls and streams that seem to burst from within.

Perhaps the most famous tepui is Auyan Tepui, or Devil's Mountain (7,872 feet), in the extreme northeast of the Gran Sabana, from which cascades the highest falls in the world--Angel Falls. The tallest tepui is Mount Roraima, at 9,094 feet, located in the southeast, where Brazil, Venezuela, and Guyana meet.

The tepuis have long intrigued scientists and explorers and inspired fantastic tales. In the sixteenth century, passions rose with the discovery of gold and diamonds, sparking the search for the elusive El Dorado. In 1595 Sir Walter Raleigh set off in quest of the city of gold and is credited with the discovery of Guyana. Although his account, The Discovery, caused a great sensation in London when it was published in 1596, Raleigh's faded mission and the brutal confrontation provoked by the British invasion of Spanish territory led to his execution in 1618.

Almost two centuries later, naturalist Alexander von Humboldt explored the Casiquiare River, which links the colossal Orinoco and Amazon rivers. This opened the way in 1840 for Robert Schomburgk, a Prussian pacifist...