The Rotunda. The name Pantheon came from the

The Pantheon
The Pantheon was built by the Emperor Hadrian between 118 and 123 CE during the high imperial period. This structure was the most influential building in the Roman Empire dedicating to all of the gods of pagan Rome. There were two pantheons previous situated at that same location, the first one built in 27 BC which was destroyed by lightning and the second burned again in 110 AD. The four main parts of the Pantheon are the Forecourt, Porch, Connecting Block, and the Rotunda. The name Pantheon came from the meaning of the word, Pan being all and theos meaning gods. The size of the huge dome was believed to represent the gods and the universe that goest on eternally in comparison with the Romans. 
The invention of concrete and the use of arches made this structure possible. It is also the development in architectural skills of the Romans that made this structure possible. The main components of this structures are, the giant dome, Corinthian columns, series of arches in support of the dome, the oculus which is the main source of light for the whole building and also symbolized the all seeing eye of Jupiter.  Romans during their time, perfected the use of arches that helped endure the enormous weight of their huge buildings and creation of domes. The dome of the pantheon is as heavy as 4000 elephants.  The roof is made out of clay in order to lessen the weight on the arches supporting it as it goes higher and it took ten years to be built. The reflection of the Romans still being influenced by the Greek culture is evident in the construction of this structure as it was built in devotion to Greek Gods.  The Pantheon was believed to be used as a temple but it is still unknown how the people worshipped in the building as it wasn’t like any other temples. The Pantheon was not only a place to worship the local Greek or the Roman gods but any kind of believer could visit and pray to any god they wanted. 
The use of the corinthians columns reflects to the use of the Greek’s architecture by the Romans but in a more developed way. The construction of the Pantheon was possible because of the use of the Greek architecture adding the Romans’ advancement in architecture compared to the Greeks. Because of the time it was built during the heir of Hadrian, this building being one of the big projects he made happen, it helped the Roman empire to thrive and prosper. The culture of the Romans were evolving from the previously Greek culture onto to their own and the pantheon could be an example of this as it is comprised of both the Greek and the Roman background in it.