You spiral down into the Catacombs of Kom el-Shoqafa, a Roman burial complex cut three levels deep into the bedrock around the 2nd century AD. The carvings are a fascinating mash-up of two worlds: Egyptian gods like Anubis shown in Roman armor, where the cultures blended underground. Lost for centuries until it was uncovered in 1900, it is the largest Roman cemetery in Egypt and the coolest, quietest stop of the day. Your guide reads the strange hybrid imagery for you.

Above ground, you stand beneath Pompey's Pillar, a single shaft of red Aswan granite nearly 27 meters tall, raised around 298 AD for the emperor Diocletian, not Pompey at all. It marks the site of the Serapeum, the great temple of Serapis that once held a branch of Alexandria's famous library. Two granite sphinxes keep it company on the low hill. Your guide sketches the Roman city that spread out from here.

You visit the Bibliotheca Alexandrina, the bold modern library opened in 2002 to honor the ancient one that made the city the knowledge capital of its age. Its tilted glass roof faces the sea, and the vast reading room steps down across eleven terraces under the light. Your guide ties it back to the lost library of antiquity, gone for two millennia. It is a hopeful, very photogenic stop.

You finish on the harbor at Qaitbay Citadel, a 15th-century fort standing on the exact spot where the Lighthouse of Pharos, one of the Seven Wonders, rose for over 1,500 years before earthquakes toppled it. Some of the lighthouse's own stone is built into the walls. The Mediterranean crashes against the rocks below, and the sea breeze is welcome after the catacombs. The views back over the harbor are the best in Alexandria.