El Petén, in Guatemala's humid lowlands, is the site of the more than 8,000-square-mile Maya Biosphere Reserve, home to Yaxhá, the ancient Maya city where the Survivor cast trekked, schemed, and camped, and Tikal, a larger and more well-known Maya site. A Guatemalan journey, particularly to these Maya sites, works best for families with gradeschoolers and teens who like eco-adventures and learning about different cultures.

While visiting off-the-beaten-path Yaxhá, a Maya ceremonial site, you're likely to encounter merely a few other visitors, as opposed to the crowds at Tikal. At Yaxhá, the dirt path winds by a green lake. Look closely and you may glimpse the bony backs and bulging eyes of crocodiles in the reeds near the shore. Campers with prior permission can overnight near the lake on raised platforms covered by thatch to block the rain.

In the morning, listen for the cries of howler monkeys. By the afternoon, they sleep in the branches of the ramón trees. Only a small percentage of Yaxhá's sites have been excavated. En route to the East Acropolis, where Temple 216 rises above the tall mahogany and gumbo limbo trees, you'll pass the ball court where the nobles played pok-ta-pok, a game that involved using their hips and thighs to bounce a ball off slanting walls in order to angle it through a suspended stone ring. The stakes were high at Yaxhá. The winners—not the losers—were sacrificed, because, as the guide explains, you give your best to the gods.

Tikal impresses with its 222 square miles and its scores of unearthed structures. Although the Maya populated this major city in 200 B.C., many of the excavated pyramids date to around 700 A.D. Some archaeologists estimate that at one time Tikal and its surrounding areas had a population nearing 100,000. Despite busloads of tourists, Tikal retains a jungle-like feel, mainly because of its vast acreage and the fact that it lies deep in the rainforest. Palm, cedar, mahogany, and other trees laced with twisty vines, line the pathways to the plazas. Spider monkeys jump from branch to branch and the occasional toucan careens onto a tree limb.

Standing in the Great Plaza, anchored by the Temple of the Jaguar and the Temple of the Masks, one may easily imagine nobles strutting through, talking politics, and plotting war. Climbing the steep staircase alongside Tikal's tallest temple, the 231-foot high Temple IV reveals a panoramic view of the gray pyramid peaks rising from the thick, green forest canopy. Like much in Guatemala, it's a memorable sight.

Tip: The trick to exploring any jungle, especially May through September, is to arrive by 7:30 a.m. to avoid both the crowds and the heat. Also, tote plenty of water, stay on the well-trodden main paths, get a guide who will give you background information, and bring change to use for the bathrooms.

(www.visitguatemala.com; www.parque-tikal.com)