The Andes mountains and beaches of the Caribbean coast are nice, but there's something a little more alluring about tropical rain forests accessible only by helicopter.

If there was one thing I'd hoped to do before leaving Venezuela, it was make my way into the heart of the country's scenic federal Amazonas Territory and the Orinoco River basin. I'd heard stories about unclad Yanomami Indians, man-eating piranhas and mosquitos the size of soccer balls. It wasn't exactly the dinosaur-inhabited plateau of Sir Arthur Conan Doyle's "Lost World," I was told, but it was the next best thing.So when the Foreign Ministry called and asked whether I wanted to join Foreign Minister Simon Alberto Consalvi and other officials and journalists on a two-day trek into the jungle, I jumped at the chance.

Consalvi was heading a government expedition to inspect border demarcation work by a joint Venezuelan-Brazilian team. Crews, with help from satellites, were re-marking sections of the nations' joint border after an 18-year hiatus. The expedition was to include a visit to Yanomami (also spelled Yanomamo) Indian villages and the landmark designating Venezuela's southernmost border with Brazil. And a reunion would be held between the explorers who discovered the area and built the landmark in 1968.

The expedition began Saturday morning when our 30-member entourage boarded a Venezuelan Air Force Gulf-222 transport plane and took off from Caracas for the Yanomami Indian village of Ocamo - named after a nearby river, which is one of the tributaries of the Orinoco River.

The flight was smooth compared to the landing two hours later on a grassy runway cut out of a jungle thicket. We were met on the runway by about 50 half- clad and curious Yanomamis. The Indians, surrounding rain forest and unbelievable humidity seemed like a scene right out of the movie "The Emerald Forest." But unlike the young, attractive Indians in the movie, it was obvious these Yanomamis had long since exhausted their gene pool.

Ocamo is home to about 500 Indians. An estimated 15,000 to 20,000 Yanomamis inhabit portions of southern Venezuela's Amazonas territory and parts of northern Brazil. Considered primitive by any standard, Yanomamis generally are passive toward strangers. But fighting among adjacent villages is common, as aggressive and violent behavior is culturally accepted and promoted.

The Ocamo Indians live off hunting, fishing and locally grown plant and "yuca" - a fibrous tuber similar in taste to a potato. Some local goods are provided by a Catholic mission located in the heart of the village.

Using spears and bows and arrows taller than themselves, Yanomamis spend much of their time hunting tigers, deer, wild pigs and monkeys.

Ocamo is the recipient of a Venezuelan government-sponsored clinic in which seven doctors shuffle their services among several local villages. The program, in its third year, has reduced infant mortality rates by 40 percent. Dr. Pedro Bravo said pneumonia, malaria, respiratory ailments and skin infections are rampant.

"It's another world here. People die very easily," he says. "We're trying to adopt medicine to them, not them to medicine. We have to tie hours for taking medication to the rising and setting of the sun - something they understand."

Several Yanomamis welcomed us into their small smoke-filled huts, or "chabonos." We then traveled across the Ocamo river in canoes hewn from trees, while locals bathed themselves in the river near its banks. We're told that flesh-eating piranha are common to the Ocamo's waters, but pose little danger in the immediate area. Nevertheless, I turned down an offer from some of my nude, new-found friends to join them for a bath.

Once across the river, it's a short walk to another gathering of huts.

The humidity is so high here that water drips constantly from the jungle vegetation. Adding to our discomfort is an array of thirsty mosquitos and other hungry insects.

We entered another clearing of chabonos to sounds of singing and chanting. After being welcomed inside another hut, I notice children playing with a dead snake in the corner while three monkeys are being smoked over charcoal embers nearby. Crude hammocks hang from the ceiling over a dirt floor - a stark contrast to metal pots placed around the fire.

When a fellow journalist attempts to set up lights to take video of the scene, Yanomami women grab their children and hurry from the hut.

Many Yanomamis sport painted faces, part of a ritual celebrating the recent death of a village member and the "passing of his spirit to another world," says a Yanomami named Luis. As is customary, Luis explains, villagers cremated the body of the deceased, then mixed his ground bones with banana and water. They then drank the mixture "out of love for the dead and for their own health."

When Luis asks me where I'm from, I tell him the United States. "Do you know where that is?" I ask. "Yes," he replies, "The other side of the sea."

Luis learned Spanish by attending school in a town upstream. Like some of the village's other youths, he has opted to wear pants and T-shirts rather than a red loin cloth. But he hasn't given up "pe," a popular tobacco-like mixture that constantly fills the cheeks of the village males.

Heavy rains slow the arrival of army helicopters scheduled to take our entourage to the headwaters of the Orinoco river in commemoration of their discovery 35 years ago. One of the helicopters finally arrives, but the trip is aborted because of irregular vibrations in a helicopter blade.

So instead, we left Ocamo in the transport plane for the Venezuelan-Colombian border town of San Fernando de Atabapo, situated near the confluence of the Atabapo and Guiviare rivers with the Orinoco.

The small town serves as a trading center with a Colombian town across the river. The trade includes a constant flow of Colombian cocaine, and villagers complain to the foreign minister about growing problems with drug abuse and trafficking.

Officers at a nearby Defense Ministry outpost say Colombian revolutionaries near the town of Amanaven about a half hour up river rely heavily on proceeds from drug trafficking. Firefights among revolutionary factions are common.

Following the visit to Atabapo, we flew north to Puerto Ayacucho for the night. The expedition continued the next morning with a flight south to San Carlos de Rio Negro. The small fishing town of 600 is located adjacent to the Rio Negro, a river of black water that serves to mark the border between Colombia and Venezuela.

At noon, our group boarded two army helicopters for the three-hour ride to Venezuela's southernmost landmark, with stops planned at the Salesiana mission of Maturaca in northern Brazil and the famed Pico de Neblina (Mountain of the Mists).

From the air, with rain forest stretching in every direction as far as the eye can see, the earth's surface takes on the appearance of a never-ending broccoli plant.

We arrived at Maturaca about 90 minutes later, where we were greeted by more Yanomamis, the local Catholic father and Brazilian explorer Dilermando de Moraes Mendes. Our arrival is a reunion for Moraes Mendes and his Venezuelan counterpart, Rene Gay Pola. The two men built the southernmost landmark shortly after its discovery in 1969.

Unlike the Ocamo Yanomamis, the Indians here all wear conventional clothing - at least while attending the mission school, where they are taught Portuguese. Father Carlos Galli has run the mission since 1971.

Yanomamis, angry with the previous father, shot him to death with bows and arrows. Galli says most Yanomamis in the area are quite primitive, and many refuse the services of the mission.

Though isolated, the area is becoming a draw for gold seekers. Galli is concerned that exploitation of local resources, including the Indians, isn't far away.

Following lunch, we lift off for the landmark about half an hour away.

To maneuver into the area, the helicopter pilots must let off about half of us at a nearby clearing and then return for us. The rain forest floor is covered with animal life. We're careful where we step, but backing from the helicopter as it takes off, I wandered into a wasps' nest and got stung several times.

The choppers returned a few minutes later, and after arriving at the landmark, we all gave it a badly needed coat of paint. As bugs and rain descend on the entourage, Mores Mendes and Gay Pola recount their arduous nine-month trek into the area in canoe and on foot in 1969 and Foreign Minister Consalvi gives a makeshift jungle press conference, simultaneously praising the work of border demarcation teams and cursing the bugs.

We're soon back in the helicopters heading for Pico de Neblina before returning to San Carlos, and then Caracas. Unfortunately, the mists for which the mountain is named prevented us from landing atop one of the 6,000-foot-high peaks.

Scientists began studying the area in 1984 and consider it a laboratory of evolution. They believe 98 percent of the Neblina's plant species exist nowhere else on earth and that some of its primitive frog species may date back to the time when Africa and South America formed a unified continent.

I took a few notes and memorized a few landmarks from the air - just in case I'm ever again in the neighborhood.