Both in high demand on the Incense Route, frankincense and myrrh resins were collected from waxy dripping “tears” of trees that grow only in southern Arabia and northeastern Africa.

Though it earned its name for the Chinese silk traded along this route, the Silk Road dealt in more than textiles, with spices from Southeast Asia and India exchanged in Jeddah and other key ports along the way.

Even before the Romans arrived in the first century A.D., the Red Sea and the Arabian Gulf saw fleets of merchants moving their prized cargo of spices — from cardamom and cinnamon to nutmeg and turmeric — around the peninsula’s ports.

One of the world’s oldest trade routes, the 2,000-kilometer Incense Route brought the rich resins of frankincense and myrrh — sourced from the waxy dripping “tears” of trees that grow only in southern Arabia and northeastern Africa — to the Mediterranean. Frankincense and myrrh were hot commodities in the ancient world. They were used to embalm mummies in Egypt to create medicine and cosmetics and perform religious ceremonies in Roman and Jewish temples and Christian churches. Demand was so strong that frankincense and myrrh were at times priced higher than gold, and the long, treacherous journey through Arabia only added to their cost.

Started more than 4,000 years ago, the Incense Route ran parallel to the Red Sea along Saudi Arabia’s west coast. The Nabateans, an ancient civilization that understood the tricks of crossing the perilous desert, profited handsomely from the passing merchants. They funneled their profits into elaborate building projects, such as Hegra (also known as Al-Hijr), a UNESCO-listed, immaculately carved sandstone city that operated as the kingdom’s second capital after Petra, which today falls within Jordan’s borders.

What remains of the city now is more than 100 wonderfully preserved tombs etched straight into the rock faces, frozen in time, and decorated with Nabataean funerary symbols that borrow heavily from the Romans and Greeks, a direct result of cultural exchange along the trade route. Evident in their architecture, the Nabateans also learned to tame the danger of the desert with impressively engineered water capture and storage systems that allowed the growing towns to develop agriculture to feed their people as well as short-stay travelers.

When the ancient Romans conquered southern Arabia in the first century A.D., they named the region Arabia Felix, meaning “Happy Arabia,” because of the extraordinary wealth accumulated from this trade route. However, the seafaring Romans, lacking local knowledge and rebuffed by the geography of the desert, soon turned their attention to the water and began developing a boat-based trade route that they could more easily control.

But even before the Romans took to these waters, the coastlines of Arabia — both the Red Sea in the west and the Arabian Gulf in the east — saw fleets of merchants moving their precious cargo of cardamom, cinnamon, ginger, nutmeg, pepper, turmeric and other spices by boat, docking in ports around the peninsula. These maritime networks linked up with land-based offshoots from the Silk Road, which ran between China and Europe. Spice shipments from Southeast Asia and India were transferred through ports such as Jeddah, nicknamed “the bride of the Red Sea” and Saudi Arabia’s second-largest city after Riyadh.

Jeddah is still a thriving port city today, thanks to seafaring traders. The architecture of Jeddah, especially in the historic Al Balad district, reflects the richness in both physical wealth and new knowledge that maritime trade brought to the city, and the beautiful buildings in this neighborhood were constructed from hand-hewn coral stone dotted with brightly painted carved latticed wood called Rawasheen.

Spices from Asia, often used in medicines, were highly prized in Europe during the Middle Ages. This trade network lasted well into the 15th century, but visitors to the city today can still browse mounds of spices, rugs, and pottery in Jeddah’s multicultural marketplaces.