Built during the 12th century, this castle was captured by the Crusaders, but in 1388 the Republic of Venice took possession. The Ottomans plundered the castle in 1397 and most of the population were taken as slaves. Later on the Venetians came back and settled in with settlers from Albania.
View from the castle is wonderful and you can see much further that Nafplio. Entrance is free, and on an August day we were the only tourists there. After reading of the history of this castle, it makes this visit more special.
Much of the area is in ruins, there are not roofs, all has fallen, but the walls are still standing, and the tower on one end offers a nice feel.
There is also a monastery below behind the castle, but it seemed to be deserted.
If you are in the area of Argos, this castle is worth a look, and it will take you about an hour and a half to drive up and view it.
Lerna is a very interesting site. An apsidal building was found there located underneath a large tumulus. There are different theories as to why it existed and why the tumulus was erected over it after its destruction. There are also smaller buildings around the large apsidal building.
The museum at Argos is worth a visit. The armor shown on the main Argos page is one of only a few complete sets found in Greece.