A joint study between Iran's Cultural Heritage Organization, the
Louvre, and the
Institut Francais de Recherche en Iran also verifies the oldest settlements in Sialk to date to around 6000–5500 BC. The Sialk
ziggurat was built around 3000 BC. Sialk, and the entire area around it, is thought to have originated as a result of the pristine large water sources nearby that still run today. The Cheshmeh-ye Soleiman (Solomon's Spring) has been bringing water to this area from nearby mountains for thousands of years. The
Fin garden, built in its present form in the 17th century, is a popular tourist attraction. It is here that the
shahs of the
Safavid Empire would spend their vacations away from their capital cities. It is also here that
Abu Lu'lu'a, the Persian assassin of the second caliph
Umar (), is popularly believed to have been buried. All these remains are located in the same location where Sialk is.
Chalcolithic Age The northern mound (Tepe) is the oldest; the occupation dates back to the end of the seventh millennium BC. The mound is composed of two levels: Sialk I (the oldest), and Sialk II.
Sialk I In the Early Chalcolithic (c. 8.2-7.4 ka BP), Sialk I is inhabited from around 6000 to 5500 BCE.
Architecture. Sialk I-level architecture is relatively rudimentary.
Pottery. Tombs containing pottery have been uncovered. The ceramic is initially rather rough, then becomes of better quality with the time.
Zagheh archaic painted ware (c. 6000–5500 BC) is found in Tepe Sialk I, sub-levels 1–2. This is the early painted ware that was first excavated at
Tepe Zagheh in the Qazvin plain. In sub-periods 3, 4 and 5, the pottery has a clear surface with painted decoration. Stone or bone tools were still used.
Sialk II Architecture. The archaeological material found in the buildings of this period testifies to increasing links with the outside world.
Metallurgy. The Sialk II level sees the first appearance of metallurgy.
Early Bronze Age The southern mound (Tepe) includes the Sialk III and IV levels.
Sialk III Sialk III () appears in the southern mound and can be divided into seven sub-periods, corresponds to the fifth millennium and the beginning of the fourth (c. 4000 BC), from the Chalcolithic into the Early Bronze. This period is in continuity with the previous one, and sees the complexity of architecture (molded bricks, use of stone) and crafts, especially metallurgical.
Sialk IV Sialk IV level begins in the second half of the fourth millennium. For the oldest sub-periods of the Sialk IV, there are links with the
Mesopotamian civilizations of
Uruk period (c. EB I) and
Jemdet Nasr period (c. EB IIA).
Architecture. The
Sialk Ziggurat is the most significant feature of Level IV, a monumental stepped platform built around 3000 BCE - arguably the oldest Ziggurat in the world. Excavations during the
Sialk Reconsideration Project (1999–2004) led by Sadegh Malek Shahmirzadi revealed that this structure was built with approximately 1.25 million mud bricks. While traditional Mesopotamian-centric views often overlook early Iranian developments, recent studies using optically stimulated luminescence (OSL) dating have been instrumental in deciphering the chronology of this "Ziggurat," confirming its position as one of the oldest such structures in the ancient world. Later on, the material is similar to that of
Susa III (
Proto-Elamite level), so this is where the Proto-Elamite horizon at Sialk is located, as is also evidenced by the discovery here of some Proto-Elamite clay tablets. Early excavations had recovered five
Proto-Elamite tablets. Like other outlying sites with Proto-Elamite writing, it was abandoned for time afterward. More recent work has found evidence on the south mound of actual occupation from the Proto-Elamite period. :"Pieces of charcoal found in one of the furnaces in which litharge fragments were found provided a radiocarbon date of 3660-3520 B.C. which introduces them as the oldest so far known fragments of such process in the ancient world." Other ancient sites in Iran from the same time have also revealed silver production, such as
Arisman, and
Tappeh Hissar. These sites are attributed to Sialk III-IV and Hissar II-III periods.
Cultural development The appearance of Uruk Grey Ware at Tepe Sialk and the related site of
Tepe Ghabristan in
Qazvin province around 3700 BCE is generally interpreted as representing a break in the local cultural sequence. This is a handmade, chaff
tempered and
Chaff-Faced Ware, that is also reported from many Chalcolithic period sites in Western Iran, upper Mesopotamia, as well as in Syria, Iraq, and the south-east of Turkey. This type of pottery suggests a widespread, transient cultural phenomenon across western Iran, potentially linked to the Uruk expansion in southwest Asia. in clay,
Susa,
Uruk period (3200 BC to 2700 BC). Department of Oriental Antiquities,
Louvre.
Late Bronze Age In the Late Bronze Age, Sialk V and VI developled. After an abandonment of more than a millennium, the Sialk site was reoccupied in the second half of the second millennium. This last phase of occupation is divided into two periods: Sialk V and Sialk VI. The archaeological material of these two levels has been mostly found in the two necropolises, called necropolis A and necropolis B. The first represents the Sialk V level. Here are found weapons and other objects in bronze, as well as jewelry, and some iron items. The ceramic is gray-black, or red, sometimes with decorations that consist of geometric patterns, and can be compared to items coming from sites in
Gorgan valley (the later levels of
Tureng Tepe, and
Tepe Hissar). ==Archaeology==