Northern Iran
Northern Iran consists of the Southern border of the Caspian Sea and the Alborz mountains. It includes the provinces of Gilan, Mazandaran, and Golestan of Iran (Ancient kingdom of Hyrcania, medieval region of Tabaristan). The major provinces, Gilan and Mazandaran, are covered with dense forests, snow-covered mountains and impressive sea shores. The major cities are Rasht, Gorgan, Sâri, Bâbol, Amol, Qaem Shahr, Gonbad-e Kavus, Anzali and Lahijan. Northern Iran has numerous villages, particularly Massulé, appreciated by travellers. Northern Iran was a trendy spot during the Pahlavi era, especially amongst foreign tourists. It was a luxurious place  that provided all types of modern recreational facilities as well as tourism infrastructure. Today, it's mostly visited by domestic tourists. Language.   Iran is a very diverse country. “Dialect wise” there are different sub-languages and dialects of native speakers in the north of Iran as well the rest of the country. From the east to the west there are five major languages and hundreds of local dialects. If you talk to a native Iranian “north of Iran” are only the provinces on the south side of Caspian Sea which are "Gilān, Māzandarān" and "Golestān, the last one" has been  separated from "Māzandarān" province at 1997. Here is the map of Iran with its provinces. Despite Iranian opinion of the north of Iran, "Khorāsan" at the east and the two "Āzerbāijān"s at the west side of Iran are geographically at the north of Iran, therefore, their languages have been included in this article. From the northeast, "Khorāsan" which is a large province laid out from the north to the middle south of Iran and is a neighbor to the Afghanistan border. The language from the north to the south of this province changes drastically, In the north of "Khorāsan" people  speak “"Ghaz Turkish"” going from the north to the middle of the province, the dialect changes to some sort of Arabic which belonged to an old Iraqi Arabic language. This language has been mixed drastically with Persian language which makes it impossible for an Arab speaker to understand it. There are some "Kurdish" speakers in the north of "khorāsan" as well. The current languages of Khorāsan. From the north of Iran heading to the west, the next province is Golestān which has its own diversity in languages. until 1997 "Golestān" was a part of "Māzandarān" province. The main languages from  the east to the west in this province are "Turkmen", "Turkish" and then Māzandarāni which is among the oldest written languages of the country. Māzandarāni "Māzandarān" is the neighboring province which has the language of "Māzandarāni" all over the province which has over tens of different dialects in different regions., almost all of them are sub categories of "Māzandarāni". Native people of "Māzandarān" call themselves "Tabari" and their language "Tabari".The name "Tapuri" / "Tabari" (which was the name of an ancient language spoken somewhere in former Tapuria) is now used in preference to the name "Mazandarani" by the young. The  earliest references to the language of Mazandaran, called Tabari, are to be found in the works of the early Muslim geographers. Al-Muqaddasī (or Moqaisi, 10th century), for example, notes: "The languages of Komish and Gurgan are similar, they use "hā", as in "hā-dih" and "hāk-un", and they are sweet [to the ear], related to them is the language of Tabaristan, [similar] save for its speediness." The next province is "Gilān, people of" Gil"ā"n have three major languages: "Gelaki, Rudbāri" and "Tāleshi" with some other old languages which are spoken in small region on "Gilān" only. In the  western side of "Gilān" people speak some sort of "Gelaki" which is heavily mixed with "Āzari Turkish", the language of the neighboring province.   After "Gilān" in the northwest of Iran, there are two "Āzerbāijān" provinces, the east and west ones, the main language is "Āzari Turkish" which is native language to the people of these provinces.   Majority of young generations of Iranian, in all over the country, are able to speak, read and write Persianwhich is a national language of the country and they learn it in schools.