7:30 a.m. Tuesday: With an early start to try and beat some of the heat, we head off for the Valley of the Kings, on the west side of the Nile outside Luxor.

It's a beautiful drive—green waves of crops (sugarcane, mostly) and palm trees line the road, and farmers are at work in their fields. Houses here are still built of mud brick, just as in ancient times.

The West Bank, our guide says, is one of the most virgin archaeological sites in the world. Almost all the New Kingdom (circa 1539 to 1078 B.C.) pharaohs built their burial places in the Valley of the Kings, cutting concealed tombs in the rock. Pyramids, they had learned, were too visible—and accessible—to thieves. Still, robbers looted most of the tombs here, stealing the treasures buried with each king.

The first tomb we enter is KV 5, built for the sons of Ramses II. Rediscovered in 1989, it's still being studied. The job will take a while—there are at least 110 chambers here.

After KV 5 the famous tomb of Tutankhamun seems very small. It was hastily prepared for the king, who died around age 20 after a brief reign (circa 1333 to 1323 B.C.). Tut would have been just a footnote in Egyptian history had it not been for the 1922 find of his intact tomb, undiscovered by robbers and still stuffed with treasures.

Nothing is left here now except Tut's mummy and coffin. (The rest is in the Egyptian Museum.) Only a few tourists are allowed in at a time, and everyone stays quiet, peering over at the coffin and wall paintings that detail funerary rituals (photo).

Next we head back out into the sun and then down again, this time into the tomb of Seti I (circa 1290 to 1279 B.C.), father of Ramses II—one of the valley's deepest, most decorated tombs.

Every surface is covered with paintings, drawings, and hieroglyphs, even the ceiling (photo). Vivid reds, yellows, and blues—they look like they were just painted yesterday. I want to touch everything.

4 p.m.: Time to go. Back to Cairo, then back to the U.S. In four days I've seen pyramids, tombs, and treasures, worn out a pair of sneakers, taken more showers than I can count—and collected a lifetime of memories.