Once in İstanbul you will obviously have to visit a mosque. Whether it can be the famous ones (i.e. The Blue Mosque, Suleymaniye Mosques) or the rarely visited ones, you will surely see some old men selling perfumes or fragrance oils in the exits of the mosques. Especially after main prayers you will encounter them in larger numbers.
These people sell perfumes that holy people tend to use. These can be fragrances that we are accustomed to or some mystic smells coming from other parts of the world. The most sold fragrance is rose as its considered spiritual and holy. This fragrance is especially preferred by pilgrims to the holy lands. Recently I have noticed regular people buying these tiny bottles of fragrances and using them on daily basis. Instead of carrying a whole bid bottle they tend to use these small bottles as life savers.
These fragrance sellers are very easy to notice with their wooden boxes usually to be located in the exit corners of the mosques especially in the historical peninsula. Here in the photo you can see at least four different variety. I personally would suggest the sellers in the Beyazit and Yeni (New) Mosques.