The fortress complex of Nafplio is extensive and imposing. The oldest fortress of all is Akronafplia, in the homonymous peninsula. On the opposite rocky hill rises the famous Palamidi. Bourtzi is found in front of the harbour, in the shallow waters, and was connected, during the old times, by chains with the land, which is also the reason it was called Porto Cadena. All three castles are remarkable not only for their arcaelogical importance but also for their incredible adjustment in the place's topography.

The city itself includes many praiseworthy monuments, such as the imposing Venetian arms depot - which is maintained intact and accomodates the Archaelogical museum -, the Mosque in Syntagmatos square, the church of Saint Spyridonas, famous because on the entrance of which Kapodistrias was murdered, the Bavarian lion, and other buildings along the mole which compose this rare architectural and urban plan whole making Nafplio distinguish as the best preserved example of a neoclassical city of the 19th century.