Iran, officially the Islamic Republic of Iran, is a country in Western Asia. Iran is bordered on the north by Armenia, Azerbaijan and Turkmenistan. As Iran is a littoral state of the Caspian Sea, which is an inland sea, Kazakhstan and Russia are also Iran's direct neighbors to the north. Iran is bordered on the east by Afghanistan and Pakistan, on the south by the Persian Gulf and the Gulf of Oman, on the west by Iraq and on the northwest by Turkey. Iran's climate ranges from arid or semiarid, to subtropical along the Caspian coast and the northern forests. The ideal time for a trip to Iran from March to October. The Official languages si Persian. Tehran is the capital, the country's most populous city and the political, cultural, commercial and industrial center of the nation. Iran is a regional power, and holds an important position in international energy security and world economy as a result of its large reserves of petroleum and natural gas.