On a sunny morning this past January, Ingo Strauch, an expert in ancient Indian history, crouches in the courtyard of what was once an Egyptian temple. The floor is littered with fallen stones and columns. Nearby, carved hieroglyphs are visible on the salt-corroded walls, which in some places still stand nearly eight feet high. Located just a few hundred steps from the glittering water of the Red Sea, in Egypt's eastern desert, this remote shrine was dedicated to the mother goddess Isis some 2,000 years ago. Today, the ruins form the most prominent feature of a barren, windswept landscape, inside a restricted military zone a few hours from the modern border with Sudan. But Strauch, scrutinizing a recently unearthed slab, is immersed in a different world. Just beneath the sand lies a once-bustling, cosmopolitan port city from which mighty ships laden with gold and wine sailed across the ocean and brought back spices, jewels, perfume and other exotic cargo in return.

In antiquity, this site, known as Berenike, was described by chroniclers such as Strabo and Pliny the Elder as the Roman Empire's maritime gateway to the East: a crucial entry point for mind-boggling riches brought across the sea from eastern Africa, southern Arabia, India and beyond. It is hard to imagine how such vast and complex trade could have been supported here, miles from any natural source of drinking water and many days' arduous trek across mountainous desert from the Nile. Yet excavations are revealing that the stories are true.

Archaeologists led by Steven Sidebotham, of the University of Delaware, have revealed two harbors and scores of houses, shops and shrines. They have uncovered mounds of administrative detritus, including letters, receipts and customs passes, and imported treasures such as ivory, incense, textiles, gems and foodstuffs such as pots of Indian peppercorns, coconuts and rice. The finds are not only painting a uniquely detailed picture of life at a lesser-known but critical crossroads between East and West. They are also focusing scholarly attention on a vast ancient ocean trade that may have dwarfed the terrestrial Silk Road in economic importance and helped sustain the Roman Empire for centuries.

The ruined Isis temple alone has yielded inscriptions and ritual offerings made by Egyptian, Greek and Roman worshipers over hundreds of years, from painted pharaohs on the walls to bronze statues and gilded figurines. But these treasures aren't what Strauch, from the University of Lausanne, in Switzerland, has traveled thousands of miles to see. Laid out before him on a blue blanket is a two-and-a-half-foot-long block of curiously inscribed white gypsum.

This article is a selection from the July/August 2024 issue of Smithsonian magazine