The nuns, driven from Tibet by Communist Chinese, live in exile at a nunnery in Nepal, but they were touring North America. When my sons arrived, exiled from the TV, the nuns were demonstrating the meditative ritual of making a sand mandala.

A sand mandala is a sacred masterpiece, a large geometrical design created meticulously with millions of grains of hand-crushed, vegetable-dyed marble.

The nuns sat silently and still for hours, leaning almost prostrate over an elaborate blueprint as they applied several grains at a time. The nuns said they don't worry that a sneeze or breeze will turn their design into dunes. They had yet to meet my 4-year-old son, Luke.

If the world were a chair, Luke couldn't live in it. His boisterous little body seems finely tuned to the fact that he's living on a rotating rock hurtling through space.

As Luke bounced precariously around the edge of the most amazing sandbox he ever saw, I was sure I was about to witness my first international incident. The nuns didn't seem to notice. Buddhists believe that practicing proper forms of concentration is the final step on the path to nirvana - perfect peace and happiness.

Apparently, these nuns are well along Buddha's path.

Buddha gave up a life of luxury to follow his path to enlightenment 2,500 years ago. He taught that people could find perfect peace and happiness by breaking attachments to worldly things.

This was long before the Home Shopping Network. And Buddha never encountered Zach, my brand-name-wearing, high-tech-craving 15-year-old son.

I thought Zach would be enthralled by the mandala. He's a talented artist. He's also the creature of a blockbuster, theme-park culture that turns beanbag toys into icons and religious objects into knickknacks.

So when he saw the mandala, he was a bit disappointed. "That's it?" he said. He figured something that takes days to construct at least would be something he could walk through. Then he found out what the nuns were going to do with the mandala when they finished it. Disappointment dissolved into disbelief.

Tuesday afternoon, after spending hours carefully constructing the mandala, the nuns swept the sand into a bowl and tossed it into a nearby lake. That's part of the ritual of making a mandala, a final act of letting go of the material in favor of the spiritual.

"But they could frame it and keep it," Zach said. "They could sell it and make some money."

I was a bit confused, too, at first. Why destroy it? But as I concentrated on the mandala, I felt a peace about it.

Someone somewhere still believes that beauty is a creation, not a collection. That holiness is a process, not a product. That what is sacred is not for sale.