Muna then places a piece of golden Najdi frankincense in the mabkhara and the sweet scent of the saffron is replaced with something smokier, something holy. It’s a rich, resinous, distinctive aroma that’s both woody and citrusy, with a touch of spice, and one that seems wholly synonymous with this country. It’s this scent that I imagine would have filled the air 2,000 years ago in the ancient port city of Sumhuram, my final stop on this perfume trail that’s taken me from Oman’s mountains to the shores of the Arabian Sea.