Naftalan is a high grade black oil, found in Naftalan, Azerbaijan. It has a high naphthalene content and is known for its use in alternative medicine. It also contains large quantities of other medicinal properties such as zinc, boron, manganese, iodine, copper and lithium. People usually sit in a bath and are covered up to their necks in the black oil.
Naftalan was first mentioned by the great Azerbaijani poet and thinker Nizami Ganjavi (1141-1201) and Marco Polo also refers to it in his treatise “On the Great Tartary”, written in the 13th century.