In Tikal, the ancient Mayan city in northern Guatemala, dawn is not seen — it is heard. First, a roar. Then a responding roar, then another and another — not from jaguars, but from howler monkeys, proclaiming their territory. A squeaking counterpoint begins: the raccoonlike coatimundi greeting one another as they forage for food. Finally the birds join in, toucans clicking their long bills and parrots shrieking, the prima donna first violins bringing the symphony to a climax.

I am listening from a narrow stone ledge, sitting with a clutch of windbreaker-clad tourists. We rode to this spot in the jungle by pickup truck, standing in the bed as it bumped along in the darkness, and then shuffled out and climbed seemingly endless flights of rickety wooden steps to the top of an ancient stone structure, Temple IV.

Now, in the dim light of early morning, a green sea of leaves stretches out before us, fog banks float about like dinghies, and only the resident leviathans, Temples I and III, dare to lift their stony heads above the horizon. Slowly, the city below the canopy begins to take shape, the hidden concert hall of moss-covered stone that has echoed this same jungle symphony every morning for more than a thousand years.

The very word "ruin" suggests a fallen city or temple, a one-time New York or Jerusalem whose inhabitants died out, taking the life of the place with them. But Tikal, surrounded by ever-creeping vegetation and screeching wildlife, and since 1996 once again used for rituals by the Mayan people, feels organic and strangely vivid. It is as if when the inhabitants of the city left, the jungle moved in, keeping it alive until the Mayans could return. Tikal has the feel of a living ruin, closer to its original vitality than perhaps any other deserted city of the past.

Among Mayan sites, Tikal has long been second banana to Chichén Itzá in Mexico, which was named one of the seven new wonders of the world in July, after a global Internet vote. (Tikal wasn't even a finalist.) But that popularity seems based on factors other than the ruins themselves. The great advantage of Chichén Itzá is accessibility, in particular, its proximity to the resort towns of the Yucatán Peninsula. It is less lively than Tikal and smaller — its centerpiece a step pyramid that is half the height of some Tikal structures.

Visiting the jungle has its drawbacks, of course. To stay at Tikal longer than a few hours on a midday trip, you must spend a night in the confines of Tikal National Park, which is impossibly humid and filled with mosquitoes. (As it was when I visited in October.) It gets better: the power goes off at night, leaving you hiding under your mosquito net and sweating into your mattress. But for my park entry fee, no ruins can match Tikal's. Some ancient sites — the Pyramids, the Colosseum — feel monumental. Others — Ephesus, Petra — feel like cities. Stand in the center of Tikal's Great Plaza, and you will have a feeling of both.

Temple I draws the eye first. A symmetrical, nine-level step pyramid on the plaza's east end, reaching 150 feet or about 45 meters, it is Tikal's iconic image, the photograph on every postcard. In AD 784, it became the burial place of the ruler Jasaw Chan K'awiil I. Turn to the south, and you see the Central Acropolis, a five-story palace where the nobles might have sat to watch plaza ceremonies or the famous Quidditch-like Mayan ball games. To the west rises Temple II, three levels and 125 feet, the burial place of Jasaw's queen, Lady Twelve Macaw. The acropolis spreads out in a complex of altars and tombs and giant stone faces constructed over millenniums, like a one-stop-shop religion superstore. All those watchful eyes — king, queen, nobles, priests — made me feel like a wayward Mayan prince, duty bound to run home and make sure that I'd skinned the jaguar correctly and that my chiseled hieroglyphs were in order.