The Old Incense Route
These would be Cane, Aden and Muza in the south and Berenice, Philotera, Myos Hormos, Leuce Kome and Aila in the North. The incense was then transported by caravan thru the desert to Petra and then to Gaza, Syria, and Alexandria in Egypt.
The road followed no fixed route as the caravans continuously moved to avoid those places which sought to tax their cargoes. The Romans bypassed the road by sailing around the Arabian Peninsula through the Red Sea rather than having to pay the Bedouin in gold or silver in exchange for the spices and incense.
They were eventually able to gain control of the road and developed it further, building wells and forts along it. But by about 42 A.D. most of the incense traffic was seaborne as it was a safer and faster passage.
The road is mentioned in the Old Testament, in Chronicles 2:9 and Kings 1:10, stating that the "Queen of the South" traveled on the "Gold and Incense Road" to meet King Solomon in Jerusalem. it is also mentioned in the Koran in Surat saba, Number 34, The Sura on Sheba. and in Surat an-Naml (the ant, Number 27).