Incense is a luxury resource. It provides commerce and happiness to the city that works it, and additional happiness if the city has a Cathedral.
Incense is a compound which, when burned, releases fragrant smoke. It is often used in religious ceremonies, and some believe that it has therapeutic benefits as well. Incense is typically composed of plant materials such as clove, cedar, frankincense, or nutmeg, but it can be created from essential oils or animal products - musk or ambergris, for example. Many early cultures employed incense, including the Chinese, Japanese, Egyptian, Babylonian, and Assyrian civilizations. Indians have used incense in religious ceremonies since at least 5,000 B.C.