section_path: Etymology
section_name: Etymology
paragraph_text: Etymology
  
  Various theories on the origin of the name Tehran have been put forward. Iranian linguist Ahmad Kasravi, in an article "Shemiran-Tehran", suggests that Tehran and Kehran mean "the warm place", and "Shemiran" means "the cool place". He lists cities with the same base and suffix and studied the components of the word in ancient Iranian languages, and came to the conclusion that Tehran and Kehran meant the same thing in different Iranian language families, as the constant "t" and "k" are close to each other in such languages. He also provided evidence that cities named "Shemiran" were colder than those named "Tehran" or "Kehran". He considered other theories not considering the ancient history of Iranian languages such as "Tirgan" theory and "Tahran" theory folk etymology.
  
  The official City of Tehran website says that "Tehran" comes from the Persian words "Tah" meaning "end", or "bottom", and "Ran" meaning " slope"—literally, the bottom of the mountain (ته کوه), referring to Tehran's position at the foot of the Alborz mountains.
  
  In English, it is also spelt " Teheran ", with both variants being used in books since at least 1800, and "Teheran" being the dominant form from after WWII until shortly before the Islamic Revolution.