Akronafplia is a term referring to a rocky peninsula and the oldest part of the ancient city of Nafplio. Here was standing the acropolis of the ancient Nafplio. Until the 13th century, it was a separate, autonomous city, but when Venetians arrived, it became a part of the defensive fortification of all Nafplio.
Many parts of the walls of Akronafplia are Cyclopean, which means that they are made with huge rocks that are adjoined perfectly. Those were the base of the defensive walls that were added on top of them later on, and they survive until today.
During the modern era, Akronafplia was used as a prison until the Greek government decided to use this spot with a magnificent view for touristic purposes. Then the prison was closed and a hotel was built instead.