9 a.m. Sunday: I've seen the Great Pyramid of Khufu a thousand times in movies and on TV, but never before in person. It's incredible—more than 450 feet (137 meters) of massive stone blocks piled high (photo). It's the only remaining of the ancient world's Seven Wonders.

Khufu ruled from around 2589 to 2566 B.C. and had this tomb built around 2550 B.C. It's still one of the largest buildings ever erected. I get goosebumps standing outside looking up at it, then wonder how I'm ever going to climb the long stairways inside.

Entering the pyramid is truly like stepping back in time 4,500 years. Not much has changed since then; there's certainly no gift shop or soda machine to greet visitors. There's not much in here, actually—no carvings or paintings. Just a narrow, ascending corridor. We have to hunch over to climb up the makeshift stairs.

Next comes a claustrophobia-inducing tunnel. We bend waaay over—nearly 90 degrees—and continue upward. I wish I were shorter. I need another shower.

We reach the erroneously named queen's chamber (its function still isn't known). We leave the small and unadorned room and head up to the king's chamber, where Khufu's sarcophagus still rests. To get there we have to climb up the famous Grand Gallery, a loooong staircase (photo), and scramble through another tunnel.

Inside, the sarcophagus, robbed and emptied in ancient times, lends the barren room a spectral air. Whatever treasures were buried with Khufu were stolen long ago.

After a while, legs shaking and completely soaked with sweat, I retrace my steps. It's disorienting to emerge from the dark pyramid into the harsh sunlight. Haze hangs over the modern skyline of Cairo just a short ways away. Giza is really just a suburb of the city, which sprawls closer and closer to the past every day.

Next: The Sphinx, Whiskey and Soda, and the Pyramid Builders >>