Cassia and Ceylon cinnamon, the two most popular types, come from the bark of certain trees, mainly grown in tropical regions like Indonesia, Sri Lanka, and India. The process of obtaining cinnamon involves harvesting the inner bark of these trees. Workers carefully strip away the outer bark and then scrape off the thin, delicate inner bark. This inner bark is then dried, which causes it to curl into the characteristic cinnamon sticks, also known as quills.