The cultural history of Prosymni can be traced back to the early Stone Age, located as it is in the Argolis Valley. Shards of pottery, spear tips for hunting and other traces of civilization can be found in the surroundings of Prosymni still today. The region continued to flourish throughout the Mycenaean period. In the surroundings of the village ceramic pots, weapons and tools, typical for that period, were made. On the mountain sides around where Prosymni is today, there were summer residences of officials in high positions. The mountains, still clad in forest, allowed for hunting game such as deer. and lion.
The environment surrounding Prosymni consists today of mountains with shrubby vegetation. Mountain sides are green during the spring but dry during the summer. Likewise Asterion River flows through this rich valley during the spring but dries out in the summer. The river and its tributaries have given the valley its special character, creating ravines and allowing for rich agriculture. Much of nature's riches in the area surrounding Prosymni was lost, though, as a result of human activities during the ancient or Roman period. Here, as with large parts of Greece, the forested mountain sides are no more. The forests disappeared sometime in the ancient times and with it disappeared its fauna. In ancient times the valley hosted capricorn, deer, wild boars. There were also wild beasts such as cave bears and lions.
During the Ancient and Roman period the valley was an area of recreation with sports centres and Roman bathhouses. Facilities such as bathhouses was, however, seen as heathen centers during the byzantine period and thus torn down. Even so, the ruins of one such bath house still stands just outside of the Prosymni Village.
During the Wold War II, German soldiers occupied greece. The German soldiers visited the village once a week to collect provisions. One day the greek partisans of the area happened upon a squad of german soldiers. The encounter resulted in the death of six german soldiers. As a result, the germans sent a troop to surround the village but the partisans had hid in the mountains and could not be found. The German troop then took revenge first by burning the village to the ground. A few days later, they returned and forced all men of the village to gather at the village square. They then chose forty young men to be brought to Argos to be executed as compensation for the six German soldiers. Fortunately, for some reason that decision was changed in the last moment and all the young men were able to return to their families. No one knows why they were let go.
Since the World War II, there have been peace in the village. Farming is the most common source of livelihood. Tobacco used to be the main cash crop which was grown in the area. In 2010, however, the European Union stopped subsidising tobacco and instead used the previous subsidies as support for the farmers to change crop. This has resulted in a shift from tobacco to citrus fruits and olives (producing Extra Virgin olive oil) as the main crop. When speaking to the villagers in Prosymni, most are positiv to the shift. In addition to the agriculture there is also some sheep farming. From the sheep you get the well-known Greek Feta cheese as well as other cheeses, which are typical for the area.
During the 80’s and 90’s an archeological team conducted research and excavations for over a decade. The findings of valuable historical objects attest the long history of the village and many of the excavated objects can be seen in the museum of Argos and the museum of Athens.