28 Places to see before you die.

The Smithsonian has posted The Life List, a list of 28 places that must be seen and experienced. I have only managed to see 3 out of 28 so far: Grand Canyon, Parthenon, and the Great Barrier Reef. I guess it time to start traveling again.

To that end, the staff of Smithsonian—as diverse a group of travelers as you're likely to meet—put their heads together to come up with an exclusive list of 28 places the Smithsonian reader might wish to visit before ...it's too late. Some of the sites are portals into the past—ancient cities so well preserved that visiting them is like stepping into a previous century. Others feature feats of engineering or sublime works of art—or, in the cases of the Taj Mahal and Frank Lloyd Wright's Fallingwater, both. Travelers can visit temples and churches so breathtaking they must have been built with divine inspiration. For the more adventurous, we offer rewards beyond mere sightseeing—from a three-day hike across the Grand Canyon to a ride along China's Yangtze River.

While all of these destinations beckon year-round, there are places where timing matters: many travelers are at a loss for words after witnessing the sun rise over Machu Picchu or seeing Iguazu Falls by the light of a full moon. And, appropriately, some of our sites now confront their own mortality—endangered by pollution or just worn down, like a few of us, by the passage of time.

Whether you visit only a couple of these destinations or all 28, your life will be enriched by the experience. And if along the way you want to gorge on caviar or get a tattoo, that's entirely up to you.