It is not found on maps, but this sprawling collection of plastic roofed-huts, swarms of flies and more than 80,000 people is probably the world's largest city of Cambodians. And it is probably not in Cambodia, although the soldiers who show visitors aroung will swear it is.

Camp 007 -- its commander insists the designation is simply a code and has no relation to James Bond -- is headquarters for one of several Khmer Seri (Free Khmer) military units that have emerged as a minor third force in Cambodia since Vietnamese troops deposed the Khmer Rouge governmnet of Pol Pot in January.

The camp stands in a wooded area where the Thai-Cambodian frontier is disputed and imprecisely marked. When three U.S. senators investigating refugees visited 007 this week, camp leaders told them they were standing on Cambodian soil but local villagers and one of the camp's senior officers have said it is well inside Thailand.

Seemingly endless lanes flanked by tiny huts with plastic roofs twist and turn across 007. From atop a small hillock one literally cannot see the end of the camp in any direction. It is easily the largest concentration of refugees in all of Southeast Asia.

People appear to be in far better health and spirits than those in Khmer Rouge camps. They sometimes greet visiting Westerners with chaotic enthusiasm, pressing so close that soldiers have to clear the way.

Despite the hardships, one senses a certain hope in the air. Camp 007 has become known across western Cambodia as a place where food is available (even if at a steep price) and where one can hope to lead one's own life, whether it involves Buddhist worship or lipstick and nail polish.

The Khner Seri camps have received scant world attention because their existence is an embarrassment to many parties -- to Thailand because it professes noninvolvement in the Cambodian conflict but tolerates these anti-Vietnamese soldiers along its border, and to the Khmer Rouge and the Heng Samrin government because the camps in many ways are a reincarnation of the old Cambodian republic, supposedly destroyed forever in 1975.

Commanding 007 is a man who said he was a captain in the 7th Division of the Cambodian republic's American-supported Army. Most of the 1,000 armed soldiers he claimed to have in the campt were veterans of that force too. Many behave as such, swaggering around with automatic weapons and striking poses of readiness when visitors raise their cameras.

As in Phnom Penh during the war, black marketing is big business. Rice, medicine and many luxury products are available at bustling black markets operated by Thais outside the camp. In the primitive clinic people die from lack of basic drugs yet outside people play tape cassettes and eat smuggled ice cream.

With fighting on the upsurge as Cambodia dries out from monsoon rains and with food supplies in the country growing tighter, 007 is growing fast. "They come every day," said a young woman at camp headquarters, "about two or three thousand a day."

one of the new arrivals was Yenn Yann, 28, a woman eight months pregnant who said she was wounded when Vietnamese forces fired on the group of 100 people with whom she was walking toward Thailand. She said she hoped to buy food there. Her husband stayed behind, sick with malaria.

Lying inside a crude shelter, with bandages on her thigh, arms and chest, Yenn Yann said food in her village in Battambang Province was in short supply, but people were not starving.

"We were eating three ladles of rice a day," she said. "It was stock left over from last year's harvest."

She estimated that this year only 20 percent of the fields around her village in the Phnom Touch area were under cultivation.

People arrive daily, but many also leave, returning to Cambodia with supplies for their families. On a trail leading out the camp's rear exist, a rarely broken chain of heavily laden people, some of them pushing bicycles, could be seen last week heading back to Cambodia.

Camp 007 was established in May and since then, according to its commander, Long Riath, it has supported itself with long-hidden gold that newcomers brought with them. Now, however, its size has become unwieldly and camp authorities have called for help from the United Nations and the International Red Cross.

Like all Khmer Seri groups, the one at 007 (it calls itself khmer Angkor, or Angkor National Liberation Movement) has grandiose plans to reconquer Cambodia from the Vietnamese and Khmer Rouge.

Long Rithia, seated at a rough-hewn wooden table, produced a document in a plastic folder heralding the formal establishment of the movement on Oct. 5. aRepresentatives from all over Cambodia had met in the camp, it said, and formulated a program of peace, independence and neutrality.

It claimed the group has more than 11,000 men and women under arms around Cambodia. In 007 a force of 20,000 was being trained, although there is not currently enough weapons.

"Even people 60 years old want to carry arms if they can get them," Long Rithia said. As he spoke officers put about 100 new recruits through drills at a nearby parade ground complete with flagpole and sentry.

Most side arms in evidence were Communist-issue Ak47 rifles. Long Rithia said most were captured from the Vietnamese, although a few were looted from Khmer Rouge arms caches identified by defectors. No foreign countries, were providing weapons, he said, but he invited his visitors to help him get aid from overseas.

Indochina watchers here generally believe the Khmer Seri receive financial support from Rhmer emigre groups. Prince Shihanouk, former Cambodian head of state who is leading a neutralist movement, has said that China and Thailand probably give assistance as well.

"As long as we can get weapons and food supplies," Long Rithia said, "we can defeat them on the battlefield."

"Them" refers to the Vietnamese. Most of 007's people despise the Khmer Rouge rule, but its troops have a working truce with them in the interests of driving out the foreigners. Observers in Bangkok are skeptical that the Khmer Seri are a serious factor in the Cambodian situation. Their claims about troop strength are thought to be exaggerated. The observers think battlefield lethargy and corruption -- the same problems that plagued the Khmer Republic's Army -- are endemic. Moreover, anticommunist Cambodians are hopelessly factionalized, incapable of uniting under a single flag, the observers say.

Several miles south of 007 is another Khmer Seri camp of 30,000 people, nominally commanded by a man who claims to be a relative of Sihanouk and who has already formed his own government. Elsewhere along the border another group headed by former Cambodian prime minister Son Sann operates.

The Khmer Seri groups appear to hope that somehow the mantle of Cambodian legitimacy will pass to them, as world opinion has strong objections to both the Vietnamese-imposed government and the Khmer Rouge. Most analysts, however, think that extremely unlikely. Yet, if the Khmer Seri can keep troops in the field through the current dry season and into the next, they might have a role to play if the Vietnamese ever seek a negotiated settlement.

For the present 007's heyday as a population center could be drawing to a close. Heng Samrin troops have moved closer to the camp, lessening its attractiveness to civilians. Moreover, the Thai government has begun moving Cambodian refugees to staging centers deeper inside the country. Current plans call for 180,000 to be moved, many of them no doubt from 007.