ARCHAEOLOGISTS have begun excavating the prehistoric dwelling recently discovered near Palmar Sur on the southern Pacific coast, the largest of its kind discovered in the country to date; they say the house is only the first find in a “megasite” that promises to divulge a vast network of structures 800 to 1,500 years old.Planting shovels where the ground was unnaturally raised in an area that has long disgorged unique artifacts, two archaeologists from the National Museum in San José and a team of students from the University of Costa Rica (UCR) have unearthed sections of a figure-eight-shaped house foundation and an entry ramp. The site is one of four established on 10 hectares of land once under cultivation by the United Fruit Company. The discovery was made in early August (TT, Aug. 12), on a site archaeologists have long suspected hides extensive prehistoric remnants.THE house is made up of two circles connected at their edges, each 27 meters in diameter, raised 1.5 meters from the ground and accessed by an 18-meter access ramp. It was suitable for an extended family, lead archaeologist Adrián Badilla told The Tico Times. It was constructed of stacked river stones pilfered from the nearby Térraba River, and raised to keep the temperamental river at bay when it swelled.The flooding river covered the site with sediment, preserving it remarkably well. Tests on ceramic shards, found with bits of stone along the edges of the raised floors where they were probably swept during cleanings, date the building to about 1000 A.D.The roof was probably conical and covered with palm fronds in the style of existing indigenous architecture found on the opposite coast among indigenous Bribrí villages.“We have to excavate and find the impressions of the posts used in construction of the roof and consult an architect” to determine the roof’s most likely shape, Badilla said.SPANISH documents from the era of the conquest describe towns of similar size with populations of 500 to 1,000. Badilla, however, is reluctant to put a number on it. “I think the field is open. It’s too difficult to make a guess at population size now,” he said.Banana company employees clear cutting the forest to make way for banana trees first noticed the site in 1938. They worked for nearly 50 years on and around hunched swathes of ground and the tops of stone globes piercing through the forest floor, having unwittingly uncovered the country’s biggest concentration of its most striking pre-Columbian artifacts – smooth, precisely chiseled stone spheres.There, they planted bananas on top of what Badilla calls a “megasite” of pre-Columbian dwellings, cemeteries, trash heaps, canals, ceramics and other artifacts.THE land, called Finca 6, passed into government hands a year ago and, where archaeologists are not uprooting buildings, the forest has been allowed to regenerate.The entire site encompasses 900 hectares,most of which is privately owned.Francisco Corrales, director of the National Museum, is drumming up support for classification of the area as a World Heritage Site by the U.N. Education and Science Organization (UNESCO).“The spheres, as a unique element, and the landscape left by the United Fruit Company, which reflects a period of importance not only to Costa Rica, but to Central America,” merit the site’s designation under UNESCO, Corrales said.The spheres, ranging in size from several centimeters to 2.5 meters in diameter, are found only in prehistoric sites in southwest Costa Rica. They have long been a source of conjecture and the impetus for news reports both within and beyond the country’s borders.“FOR their size, perfection and quantity, the Costa Rican spheres are unique in the world,” Badilla said.They have spawned elaborate theories about their possible purpose, and there is hardly a report about them that doesn’t include the word “mysterious.”However, Badilla used the spheres as road signs pointing to the underground archaeological sites on which they rest, and considers the artifacts symbols of rank and cultural identification.“The spheres need to be studied in their indigenous context,” Corrales said. “When they are seen alone, removed from their sites, there are people who have all kinds of strange theories, but they can be understood as part of the indigenous culture.“Unfortunately, the site where the most of them were found was on banana company land. We can’t study the spheres in the sites and positions where they were left,” Badilla said. Many were cleared off the land when it was under cultivation, moved to San José, where the National Museum itself displays about a dozen, or out of the country.By early next year the site could be ready for limited visitation. The National Museum has begun training willing people in the surrounding community in the history of the region, how to protect the site and how to prepare it for tourism.