Semnan province (Persian: استان سمنان) is one of the 31 provinces of Iran. It is in the north of the country. Its capital is the city of Semnan.
The province of Semnan covers an area of 96,816 square kilometers and stretches along the Alborz mountain range, bordering on Kavir desert in its southern parts. The province was made part of Region 1 on 22 June 2014, as the provinces were grouped into 5 regions for coordination and development purposes.
South Khorasan province (Persian: استان خراسان جنوبی) is one of the 31 provinces of Iran, located in the eastern part of the country. Its capital is the city of Birjand. In 2014, the province was placed in Region 5. This province is bordered to the north by Razavi Khorasan Province, to the northwest by Semnan Province, to the west by Isfahan and Yazd Provinces, to the south by Kerman Province, and to the southeast by Sistan and Baluchestan Province. The area of this province is 151,913 square kilometers (58,654 square miles), making it the third largest province in Iran after Kerman and Sistan and Baluchestan. According to the 2016 census, South Khorasan's population is 768,898, making it the fourth least populous province in the country. With only about 5 inhabitants per square kilometre or 13 inhabitants per square mile, it is the most sparsely populated province in Iran.
South Khorasan Province is split into two distinct regions: the "mountainous and elevated" areas in the north and northwest, and the "low and flat" central and southern plains. The tallest mountains in the province include "Kamarak" and "Shah Kuh." It experiences a "dry and desert" climate, which can be further divided into "hot and dry" and "mild and dry" categories. The northern and northwestern parts are more fertile, while the southern and southwestern plains endure a dry and harsh climate. The rivers in this region are seasonal, with no permanent rivers present.
Mazandaran province is one of the 31 provinces of Iran. Its capital is the city of Sari. Located along the southern coast of the Caspian Sea and in the adjacent Central Alborz mountain range and Hyrcanian forests, it is bordered clockwise by Russia (across the sea), Golestan, Semnan, Tehran, Alborz, Qazvin, and Gilan Provinces. Mazandaran covers an area of 23,842 km.
The province has diverse natural resources, notably large offshore reservoirs of oil and natural gas. The diverse natural habitats of the province include plains, prairies, forests and rainforest stretching from the sandy beaches of the Caspian Sea to the rugged and snowcapped Alborz sierra, including Mount Damavand, one of the highest peaks and volcanoes in Asia.
Dasht-e Kavir (Persian: دشت كوير, lit. 'Low Plains' in classical Persian, from khwar (low), and dasht (plain, flatland)) or the Kavir Desert, also known as Kavir-e Namak or the Great Salt Desert, is a large desert lying in the middle of the Iranian Plateau. It is about 800 kilometres (500 mi) long by 320 kilometres (200 mi) wide with a total surface area of about 77,600 km (30,000 sq mi), making it the world's 24th largest desert. The desert stretches from the Alborz mountain range in the north-west to the Dasht-e Lut in the south-east. It is spread across the Iranian provinces of Khorasan, Semnan, Tehran, Isfahan and Yazd.