The Greek war for independence (in the 1820's) began on the Peloponnesian peninsula. Before it spread to the mainland, Navplion was chosen as modern Greece's first capital. The enormous fort atop the mountain was built as an outpost by the Venetians in the 16th century. The Greek people really didn't like the Venetians very much, so the Venetians stayed cooped up in forts like this during their brief attempt at creating an empire. The strategy didn't work so well.