PUNO, Peru — In the beginning, there was a lake cradled in the mountains of a high plateau in the Andes. How it got here was simple: The universe cried, and its tears flooded the world. Mankind had disobeyed the gods, and the gods sent in pumas. Lake Titicaca — literally, pumas of stone — is proof, tragedy burnished into beauty.

Standing on a quay in Puno, a city on the lake’s western shore, my wife, Margie, and I stared at its cerulean expanse, an autumn sun reflecting off what has been called the eye of God. Not a breath of wind stirred the water, the Donald Duck and Goofy paddle boats imperturbable. Our Peruvian itinerary had included Machu Picchu, but this morning vista surpassed the splendor of those ruins, whose images on calendars and coasters, snow globes and refrigerator magnets are burned so deeply in the mind that the reality seemed almost derivative. There was no mistaking the originality of Lake Titicaca, straddling Peru and Bolivia. It seemed less terrestrial than something borrowed from the sky, and on that morning it held the world in its grasp, its mirror-like stillness soon rolling in the wake of a water taxi.

Our destination was Luquina Chico, less than 90 minutes from Puno, where I — along with students and professors from Chapman University in Orange, where Margie teaches — would stay with local families for two nights. The students, drawn by the lure of three units, were promised the opportunity to “explore the Peruvian leadership approach to community development,” but the lessons were greater than this.

The residents of Luquina, increasingly dependent on visitors like us, know that unregulated tourism — an easy temptation in a region as beautiful and undeveloped as this — can tear apart communities. They are trying to develop a sustainable model that gives every household an opportunity to prosper and preserves the tranquility of the village. Finding that balance is not easy.

Although most travelers will not visit Peru as part of an education tour, what we saw and experienced — service learning — is available to anyone willing to pack, as we did, a pair of work gloves. Lake Titicaca, an hour and a half by plane from the capital Lima, is a world apart in politics and culture. When we were here, in spring 2018, President Martín Vizcarra had just been sworn in (he went on to dissolve Congress this September), but the focus in Puno then was a football match between Peru and Croatia. Peru won.

Our guide was Edgar Frisancho, whose agency, Edgar Adventures, is one of a few companies in Puno that arranges tours of the lake. Frisancho was born in central Peru and moved here when he was 16 to escape the violence of Shining Path revolutionaries. Thirty years later, he speaks easily about the region’s history and of traditional values shifting under economic pressures. Lake Titicaca, he said, “has seen more changes in the last 30 years than in the last 500 years.”

The conquistadors’ encounter with the Incas was violent and cruel, but what is occurring today is as dramatic and irrevocable. It stems not just from environmental changes, the internet or even the building of roads, but from visitors like us and the villages that compete for our attention.