The castle of Palamidi lies on a high hill (216m. a.s.l.) to the east of Acronauplia which was first fortified by the Venetians during the second Venetian occupation of the area (1686-1715). It is a typical baroque fortress, based on the plans of the engineers Giaxich and Lasalle. In 1715 it was captured by the Turks and remained under their control until 1822, when it was liberated by the Greeks.

The most important monuments of the site are:

- The Castle. Venetian defensive structure dated to the beginning of the 18th century. It consists of eight bastions surrounded by walls. A long stairway reinforced with small battlements starts at the foot of the NW slope and leads up to the fortress on the top of the hill.

- Church of St. Andrew, built in one of the bastions of the fortress. It is a barrel-vaulted church with the eastern half built under one of the arches supporting the walls. Its free-standing part is two-aisled.

- The prison of Kolokotronis. One of the bastions, the so-called "Miltiades" was used as the prison cell of Theodoros Kolokotronis, a hero of the Greek Revolution.