More than 1,500 years ago, Maya priest-kings built dozens of pyramids just tall enough to poke above the suffocating jungle here and reach the cooling breezes of a nearby lake.
They also carved dozens of stone monuments, erected handball courts and laid out the streets of their city in a grid, a departure from the sprawling confusion of most other contemporaneous Maya cities.
It was supposedly the third-largest city in the Maya empire, a bustling trade and ceremonial hub 20 miles from Tikal, one of the greatest centers of Maya culture.
What a difference a millennium makes.
Today, Yaxha is an obscure cluster of oddly shaped hills covered with vines and towering trees. Troops of howler monkeys scramble through the treetops, fighting for space near the lake. The only sign that it was once a great center is a single weathered gray pyramid.
Like hundreds of other Maya cities, Yaxha remains largely unrestored and neglected, moldering away in the vicious heat and soaking rains of Guatemala's vast northern territory called the Peten.
It is difficult to imagine a newly discovered pyramid in Egypt sitting untouched and unexplored. Yet that is what happens with thousands of Maya sites throughout Central America.
"We simply do not have the resources to investigate them all," said Luis Fernando Paniaqua, head of the government's Department for the Registration of Cultural Property, which tracks Maya artifacts.
There is sporadic exploration, mostly on the part of joint Guatemalan and foreign teams. A German team works in Yaxha. Farther north, researchers from UCLA join with Guatemalan archeologists at El Mirador, a site near the Mexican border far more remote than Yaxha. (The Maya empire sprawled from modern-day Mexico into Honduras.)
Still, many more sites remain untouched. In the far northwestern corner of Guatemala, there is a cluster of Maya sites that have been discovered but remain unexplored.
Paniaqua said he believes that the sites have been visited repeatedly by grave robbers from the Mexican side of the border and that there is little the Guatemalan government can do about it.
"It's an economic problem," he said. "These sites are deep in the jungle. There's no infrastructure. It's difficult to put any guards out there."
By some estimates, there are more than 2,000 Maya sites in Guatemala alone, of which only one in 20 is guarded.
For instance, UCLA has hired 27 of its own guards to protect El Mirador, which is thought to have been the largest city in the Maya empire.
"If we didn't do it, we'd lose the whole city," said Richard Hansen, a UCLA archeologist who heads the exploration efforts at El Mirador. "There's tremendous pressure from not only looting but deforestation and wholesale plunder."
But even with guards, the sites often fall prey to tomb raiders, who are so ubiquitous that Latin American Spanish has a word for them: guaqueros. In September 1997, a gang of grave robbers killed an unarmed guard at Yaxha and stole four pieces of pottery, each more than 1,000 years old.
About five years ago, according to guides at the site, another gang of robbers slipped in and removed a beautiful and intricately carved stone monument at the base of one of the unexcavated pyramids.
"They have taken a lot of stuff out of here," said Manuel de Jesus Alvarenga, one of the guides.
Such stories are common. Take, for instance, the site at El Zotz (The Bat), named for a sheer cliff nearby that each night disgorges thousands of bats from its crevices.
Though a national park, the site is unreachable by car, accessible only after a full day's hike. It is filled with half-excavated pyramids and tombs, most of them covered with dense brush.
Older chicleros--local residents who work deep in the jungle in search of a special tree's sap, used to make gum--claim that in their youth, a large bell made of jade hung in the top of one of the temples. At night, when the wind blew, the bell could be heard ringing for miles, as it had for thousands of years. The bell has long since vanished.
"Most governments don't like to spend a lot of money protecting archeological sites," said Julia Sanchez, the assistant director of the Cotsen Institute of Archeology at UCLA. "They're more interested in feeding people and building schools."
One of the problems is that such sites are difficult to reach. Yaxha, for instance, is at the end of a long and dusty three-mile road where tourists have occasionally been pulled from their cars and robbed. There is a lodge nearby but little else in the way of creature comforts.
Locals hope that increased tourism will bring in more money and perhaps more interest in restoring and protecting the sites. With support from the Guatemalan government, Yaxha has become a stop on the eco-tourism circuit in recent years, and the number of visitors has climbed to as many as 150 a day.
"The road doesn't have any pavement and people don't know much about this site," Alvarenga said. "But we hope one day that it'll be as big as Tikal."