The Pyramids and Sphinx at Giza. They are every bit as impressive as you expect, and bigger. The Great Pyramid is the last surviving Wonder of the Ancient World, and standing at its base -- feeling the sheer mass of 4,500-year-old limestone blocks -- is a humbling experience. The Sphinx sits just below, gazing east across the Nile Valley. Go early in the morning or late in the afternoon to avoid the worst crowds and the midday heat. The sound and light show at night is atmospheric, if a bit cheesy.
The Valley of the Kings in Luxor. The pharaohs of the New Kingdom were buried in this desert valley on the west bank of the Nile, and the painted tombs are extraordinary. The colors on the walls look like they were finished last week, not 3,000 years ago. The tomb of Tutankhamun is here, along with dozens of others. Across the road, the Temple of Hatshepsut is carved into the cliff face and worth the visit. A combined morning on the West Bank, covering the Valley of the Kings, Hatshepsut's temple, and the Colossi of Memnon, is one of the great mornings in all of travel.
Karnak Temple Complex. Also in Luxor, on the east bank. This is the largest religious complex ever built -- construction continued for over 2,000 years. The Hypostyle Hall, with its forest of 134 massive columns, is breathtaking. Give it at least two hours. Luxor Temple, a short walk along the Nile, is beautiful at sunset and dramatically lit at night.
Abu Simbel. Ramesses II carved four colossal statues of himself into a cliff above the Nile, guarding Egypt's southern border. The entire temple was moved in the 1960s to save it from the rising waters of Lake Nasser -- an engineering feat almost as impressive as the original construction. It is a long trip from Aswan (a 3-hour drive each way, or a short flight), but unmissable.
A Nile cruise between Luxor and Aswan. Three or four days on the river, stopping at temples -- Edfu, Kom Ombo, Esna -- and watching the green ribbon of the Nile Valley slide past. Feluccas (traditional sailboats) offer a more intimate version of the journey, sleeping on deck under the stars. This is how Egypt has been traveled for centuries, and the river is still the best way to understand the country's geography.
Red Sea diving and snorkeling. The coral reefs of the Red Sea are among the finest in the world, and the water is warm and clear year-round. Hurghada has the most dive operators, Sharm el Sheikh has Ras Mohammed National Park, and Dahab has the Blue Hole and a backpacker scene. Even if you don't dive, the snorkeling is superb -- some of the best reefs are accessible right from shore.
Siwa Oasis. A remote oasis near the Libyan border, Siwa feels like a different world. Salt lakes shimmer in the desert, date palms fill the valley, and the ruins of the ancient oracle temple -- where Alexander the Great came to consult the gods -- sit on a rocky outcrop above the town. Getting there takes effort (an 8-hour bus ride from the coast), but the solitude and beauty are worth it.
Islamic Cairo. The medieval heart of Cairo is dense with mosques, madrasas, and caravanserais spanning a thousand years of Islamic architecture. Al-Azhar Mosque, founded in 970, houses one of the world's oldest universities. The Sultan Hassan Mosque is monumental. The Khan el-Khalili bazaar has been a marketplace since the 14th century and is still buzzing with commerce, tea, and conversation. Allow a full day to wander.