Cairo

The Great Pyramid of Giza stood for over 3,800 years as the tallest structure humans ever built. It took 2.3 million stone blocks, some weighing as much as 80 tons, to construct a tomb for Pharaoh Khufu around 2560 BC. The pyramids sit just outside modern Cairo, but the city itself is much younger.

Cairo got its name from Mars. When the Fatimid general Jawhar laid the city's foundation stones in 969 AD, the red planet was rising in the night sky. The founders called their new capital al-Qahira, "the Vanquisher," after the conquering star overhead. They believed Mars would make their city undefeatable.

The Fatimids also built Al-Azhar Mosque in 970, and by 988 it became a university. Over a thousand years later, it's still teaching students today.

Saladin, the famous warrior who battled the Crusaders, seized power in 1171 and started building a massive fortress called the Citadel on the hills above the city. He dug a well 85 meters deep to supply water. That's taller than a 25-story building, straight down into rock.

The Citadel served as Egypt's headquarters for nearly 700 years. By 1340, Cairo had grown to 500,000 people, one of the biggest cities on Earth.

Then in 1347, a ghost ship drifted into Alexandria's harbor with its entire crew dead. The Black Death had arrived. Within eight months, one-third of Cairo's population was gone.

The plague kept returning every nine years or so, striking Egypt 58 times over the next 170 years. The city took centuries to recover.

While you're in Cairo, get lost in the Khan el-Khalili bazaar, a maze of narrow alleys where merchants have sold spices, lanterns, and perfumes since 1382. Haggling is expected, so practice your negotiating skills.

Climb to Saladin's Citadel for views of the city's thousand minarets. Order koshari, Egypt's national dish: a giant bowl of rice, lentils, macaroni, and chickpeas buried under tomato sauce and crunchy fried onions. It's messy. It's delicious.

Try taameya, Egyptian falafel stuffed into warm bread, and wash it down with cold hibiscus juice that turns your tongue bright red.