Temple of Isthmia

The Temple of Isthmia is an ancient Greek temple on the Isthmus of Corinth dedicated to the god Poseidon and built in the Archaic Period. It is about east of ancient Corinth, at the site of ancient Isthmia. It appears to have been constructed in the seventh century BC though was later destroyed in 470 BC and rebuilt as the Temple of Poseidon at Isthmia in c. 440 BC during the Classical period.
History.
Around the turn of the 8th to 7th century BC, it is apparent that there is the emergence of a new period in both Greek architectural and artistic history. Corinth was at the centre of this with its development of new pottery design, settlement planning, military organisation and most significantly being the possible birthplace of monumental buildings and a new style of Architecture known as the Doric order. 
The date of the Archaic temple’s construction is important then as it establishes when monumental architecture began as well as when the transition from Iron Age architecture to Doric occurred. This was also the point where the Greek temple as a whole became a defined form.
The site of the Temple of Poseidon at Isthmia was one of great activity up until the 3rd century AD. It was a Panhellenic sanctuary and the last location of one of the four Pan-Hellenic Games from the sixth century (around 581 BC) to be found, and had numerous buildings constructed in its vicinity. These ranged from Roman baths to a theatre and most importantly two temples. The Archaic temple was the first erected and was destroyed by fire in 470 BC; the site of the temple was then rebuilt upon, resulting in a larger temple constructed directly on top of the Archaic in the Classical period, which was also destroyed by fire, this time in 390 BC. 
The Isthmian Games which were held near the Temple of Isthmia in honour of Poseidon was one of the four great Athletic Festivals of Ancient Greece, alongside those of Zeus at Olympia and Nemea, and those of Apollo at Delphoi. 
The games was mentioned by Callimachus in the 3rd century BC:
Pausanias described the sanctuary in the second century:
If still in use by the 4th-century, the temple would have been closed during the persecution of pagans in the late Roman Empire. The temple of Poseidon was most likely sacked and destroyed in the invasion of the Peloponnesus by the Visigoths in AD 396.
Archaeology.
Excavations of the site were conducted in both the original 1952 excavations, and again in 1989. The latter excavations helped to uncover evidence relating to all the areas of development of Isthmia from the Bronze Age to the Roman period, but in particular focused on the Archaic temple, partly because this is the most complete of the buildings found at the site despite being one of the oldest.
The site was originally found by Oscar Broneer in 1952 with excavations continuing until 1967. He published his findings in a series of three volumes starting in 1971, and in articles in the "Hesperia Journal". He dated the temple to about 700 BC and produced a reconstruction of the temple which featured a wooden peristyle in the Doric style. 
Between August 16 and November 29, 1989 a new period of excavation was undertaken, mostly to clear up some of the disputes that had arisen over the conclusions Broneer had made on his finds. The first report of the 1989 findings was published in "Hesperia" in 1992, with subsequent reports following in later years and has contributed to the debate which primarily focuses around the dating of the temple, but also includes the nature of its layout and general usage and development.
Dating.
The debates that occurred after the first publication of Broneer's results focused on his inclusion of a wooden peristyle of the Doric order, and a construction date of c. 700 BC. Historians such as J. B. Salmons in his book "Wealthy Corinth " (1984) stated that the temple was constructed under the reign of Cypselus; this contradicted Broneer's suggestions as Cypselus did not achieve power until 657 BC, and so would put back the creation of the temple by about 50 years. Furthermore, it was disputed whether the temple was even Doric in design and the proposed plan of Broneer detailing the temples foundations had little evidence in support.
The 1989 excavations contained important discoveries that helped to establish that the temple was actually constructed later than Broneer had anticipated, and puts it at a date that ranges from about 690 to 650 BC. This date would mean that it could have been possible for it to have been constructed during Cypselus’ reign, as well as suggesting a later date for appearance of monumental buildings. The excavations achieved their results through a variety of methods. Prior to the excavations topographical and stratigraphical investigations were carried out of the known buildings under the surface. When digging commenced trenches were made, for the most part extensions on Broneer’s original trenches. The soil that was collected was then both dry sieved and wet sieved and from this many finds were made. Deposits containing large amounts of pottery, ashes as well as stone foundations were all found which helped to determine answers to many of the questions that had been raised. The Ceramics recovered helped to ascertain a more accurate date, this was through the finding of pottery such as that of the aryballoi style, which is an effective means of dating owing to their introduction at the beginning of the seventh century. Furthermore, the ground plan and surrounding features of the site were now able to be mapped with a good degree of accuracy. In the reports, this fact that the temple floor plan could be reconstructed accurately is mentioned as the most important find of the 1989 excavations. The ground plan showed a temple that was of unrivalled proportions for its time and of a layout that was almost entirely new. This therefore showed the origins of monumental buildings on the Greek mainland and provided an approximate date. Also though it further established that there was no evidence for the employment of the Doric style as suggested by Broneer. Although Broneer stated of his reconstruction that it was speculative, and still appears to have no evidence in support its existence, this does not mean the temple was not one of the pioneering buildings featuring Doric architecture. This is because all that is known from the temple is what has been found in deposits of pottery and the stone foundations, as the temple was completely destroyed in 470 BC (also known from pottery discovered during excavations, particularly burnt pottery). There is little that remains other than the floor plan, or at least that has been found thus far, and so the actual style is hard to put any firm conclusion to. It is however apparent from the excavations though, the layout of supporting pillars and dimensions, which beyond doubt can tell us that it was a temple of epic proportions for its time.
Ultimately the importance of the Isthmian site stems from the fact that almost all the knowledge of the Archaic temple comes from archaeology. There are few references in contemporary Greek literature, for example in Herodotus’ "The Histories" there is mention only of Cypselus’ reign in passing, being one of great prosperity, and of the battles and beginning of the Pan-Hellenic games at Isthmia. This means that when studying the origins of Greek monumental architecture and the Doric order and such like, the archaeology remains the only real source of information. In this respects the temple at Isthmia is key in looking at these early developments and the 1989 excavations helped to establish details concerning dating, size and style. From this further study can now be undertaken such as who built the temple, as suggested earlier Cypselus is noted as a candidate but it could well have been before his time. Furthermore, future excavations may be able to uncover more evidence on the temples relation to Doric architecture and so overall bring together a clearer picture of the changes that occurred as Greece moved on from the Iron Age into the Classical period.