Traditionally, the Tehran bazaar was split into corridors, each specialising in different types of goods, including copper, carpets, paper, spices, and precious metals, as well as small traders selling all types of goods. Today, modern goods are available as well, in addition to the many traditional corridor traders that still survive. It is located In Arg Square and the main entrance is Sabze meydoon.
The Grand Bazaar is located in southern Tehran; its many corridors are over 10 km in length. There are several entrances, some of which are locked and guarded at night
The area around Tehran has been settled since at least 6,000 BCE, and while bazaar-like construction in Iran as a whole has been dated as far back as 4,000 BCE, Tehran's bazaar is not this old. It is hard to say exactly when the "bazaar" first appeared, but in the centuries following the introduction of Islam, travelers reported the growth of commerce in the area now occupied by the current bazaar. The Grand bazaar is a continuation of this legacy. Research indicates that a portion of today's bazaar predated the growth of the village of Tehran under the Safavids' dynasty, although it was during and after this period that the bazaar began to grow gradually. Western travelers indicated that by 1660 BCE and beyond, the bazaar area was still largely open, and only partially covered.
Despite relying heavily on this historical legacy, much of the bazaar itself was constructed fairly recently. The oldest remaining buildings, walls and passages in the bazaar today very rarely exceed 400 years, with many being constructed or rebuilt within the last 200 years. The bazaar grew as a "city within a city" for much of the 19th century, and was largely able to expand itself without much outside interference. However, as Tehran began to grow exponentially in the early 20th century under Reza Shah, the changes brought by this rapid expansion saw much of the bazaar (including such areas as the Perfume Sellers Bazaar and Moat Bazaar) disappear.
The old sections of the bazaar are generally similar in architectural style, while parts added in the 20th century often look markedly different; critics say that less care was taken in the construction of later sections. However, in an effort to increase the prestige of the bazaar, projects to beautify the bazaar through the use of plaster moulding and decorative brickwork were undertaken late in the 20th century.