(IRAN: مسجد سلیمان) is a city in the Khuzestan province in southwestern Iran. The first modern oil wells of the Middle East were discovered and drilled in this area. It is mostly populated by the Bakhtiari Lur people with estimated population of 127,634 in 2005.

The name of the city is assumed to have its origins from a belief of local inhabitants calling the ruins of an Achaemenid palace as the Irsoleyman, which means "Mosque of Solomon."

The primary settlement of the city formed about 100 years ago as a result of petroleum industry development in the Middle East when the first negotiations on the establishment of the Anglo-Bakhtiari Oil Company were in progress between William Knox D'Arcy representatives and Bakhtiari Tribe leaders (Khans).

In 1908 the first oil well in the Middle East was drilled in the region of Naftoon in the center of this city, so the 100th year anniversary of oil drilling in the Middle East was celebrated in 2008 in this city.

The historical name of the city is "Parsoumash", this name was given to this city by "Persians" who came from the west to this area.
During medieval times it was called "Talghar", the name of a land in the vicinity of Karoon river. Later on the city was called "Jahangiri" , then "Naftoun", and finally Masjed Soleyman .

When Arabs attacked this region, they intended to destroy the fire temple in this city, but they encountered objection and resistance. It is said that "Moses" established "Sar Masjed" fire temple to develop his religion and it was respected by the population.

The name of the city was changed to Masjed Soleyman after Mohammad Reza Pahlavi's visit in 1303 solar year.

It is also believed that this was the birth place of "Kourosh" the king. In 1287 solar year there was a big turn in Middle East by exploring Oil in Masjed Soleyman. The city became a company city when British experts moved in. The culture of the city was also influenced by the British empire.

2000 national monuments are expected to exist in this province and the towns around , about 400 of them have been found and excavated.

Besides Karoon, there are some other rivers in the city such as "Shour", "Tambi", and "Cham Asiyab".
The majority of the population is Bakhtiyari tribes , whom are living on the slope of Zagros Mountain. "Gelim", "Chogha", and "Khersak" are among the handicrafts of this region

Sar Masjed fire temple
Professor Grishman believes this monument is related to the Persian era and he also believes that this temple is older than "Pasargad" castle or even "Perspolice". He notes that this monument is related to 8th century B.C.
Bardneshandeh temple "Bard" in Bakhtiyari Language means "stone" which is in a column shape installed in the earth. The height is 3.5 m and the thickness is 50 cm.
Archaeologists believe that this is the oldest open temple in Iran. The carving of the temple is related to Achaemean. The monument is located on the route from Masjed Soleyman to Andika.

Zarin Kalgeh
In this monument there are remains of walls made of stone and plaster. The length of the wall is 250 m and the width is 150 m. There are paintings and designs on the wall implying a religious message.

The foreigner's cemetery
In the vicinity of "Zaman Abad" village, there is a cemetery for American and British. There is also another Armenian cemetery located in "Naftoon" quarter.

The old sirens
The fire department of the oil company is located opposite Nazaja department. An alarm went off for waking the labours and also it was a sign of starting and finishing work.
This siren left sweet memories for people inhabiting in the region.

Beautiful building of oil company
The Oil company hospital located in "Kalge" was constructed in 1303.
It is the first and the most well equipped hospital in the country.
The first and best well equipped golf club is located in "Bibiyan" quarter in Masjed Soleyman.
The athletes of this club are still the best golf players in the country.
The railway is located on the border of Karoon River in Masjed Soleyman city center. It is counted as the first railway of the country.
The railway transported the equipment and the goods to industrial establishments in Masjed Soleyman, which had been carried by ships through Karoon River and anchored in Darkhazineh 100 km away for Ahwaz.