By TIM McDONALD
The Associated Press

LA BREA, Trinidad -- A stone's throw from the sparkling blue Gulf of Paria, on the southwest coast of this lush island, squats what is probably the ugliest tourist attraction in the Caribbean.

It burbles, hisses and occasionally spits fire. You smell it before you see it as you bounce over undulating, pock-marked roads. And if you didn't know it was a tourist attraction, you might hold your nose, avert your eyes and step on the gas.

The Amerindians believed the lake formed because of punishment from the gods. To modern Trinidadians, Pitch Lake in the southwest of the island is a source of income from tourism and mining.

Some 55 miles (90 kilometers) from Port-of-Spain, it is the largest natural asphalt lake in the world -- and well worth a visit if only for the sheer incongruity of a giant tar pit in the midst of tropical beauty.

The Trinidad Lake Asphalt Co. exported $3 million worth of pitch to more than 50 countries last year, according to the Ministry of Trade and Industry.

But the lake is also a tourist attraction, drawing nearly 20,000 people last year, almost half of them foreigners. The circular lake is approximately 100 acres (40 hectares) and 250 feet (75 meters) deep at the center. Underground ribbons of asphalt seepage coil out from the depths, causing serious erosion problems to roads and buildings in the nearby town of La Brea. The word means tar or pitch in Spanish.

Watch your step

Most of the lake itself is hard enough to walk on, but if you try it without a guide, you might happen on the central section that could swallow a car -- a part that looks much like the hard surface.

''Walk right behind me,'' says guide Devon Fredrick. ''Step where I step.''

The heavy mining equipment that borders the south and east rims of the lake does little for the ambience.

But beauty flourishes in the surroundings: Cashew trees ring the lake, and guava, mango and breadfruit trees have found a way to survive. Water rose, nymph lilies and bird of paradise grow naturally out of the muck.

Herons are everywhere, eating the algae that grows under pockets of water, along with hummingbirds, sandpipers and kingfishers. Locals say that during the dry season, when the sun bakes the skin of the lake, ospreys drop freshly caught fish to cook on the broiling surface.

They also believe the rainwater that collects in nooks and crannies on the lake has miraculous healing powers.

''It's good for rheumatism, arthritis, joint pain, all sorts of things,'' Mr. Fredrick says, splashing the green- and yellow-tinged water on his face. ''People come down and bathe in it. Your own personal Jacuzzi. Make you sleep like a baby.''

The water has a high sulphur content. That may be the source of the belief in its curative powers -- elemental sulphur is relatively harmless to humans, but toxic to many bacteria -- but it is also responsible for the rotten-egg stink. It is that smell that in 1820 caused Gov. Sir Ralph Woodford to give up on the pitch as a fuel. According to the curators of the lake's museum, Sir Ralph tried to use the stuff to light a beacon in the tower of Trinity Cathedral in Port-of-Spain. But the smell was said to be unbearable, and he abandoned the idea.

One of three in world

The lake was formed when crude oil seeped to the surface through fissures in the earth's crust millions of years ago. The lighter elements in the oil evaporated, leaving behind the heavier asphalt.

Pitch Lake is one of three natural asphalt lakes in the world, the others being in California -- the famous La Brea Tar Pit -- and Venezuela.

The Chaima Indians had other ideas about how the lake was formed. After a victory over a rival tribe, the tribe was carried away with its celebration, cooking and eating the hummingbirds they believed held the spirits of their ancestors. Thus, legend has it, their winged god opened up the earth and conjured up a lake of nasty pitch to swallow the village.

Amerindian pottery has been found, along with the remains of prehistoric animals such as the mammoth and what is believed to be the tooth of a giant sloth.

For those interested, the lake will be around for a while: It holds reserves of 6 million to 10 million tons, which at the present rate of extraction would last 400 years.

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