The Venetian fortress, known as Bourtzi, is considered as the trademark of the town. It was built by the Venetians in 1417 and its first name was Castello dello Soglio. It consists of a tall octagonal tower and it is surrounded by semicircular towers. The entrance of the bay used to close with a movable chain, so " Porto Gardena ", the port of the chain, was a safe place.

In 1865, Bourtzi wasn't a fortress anymore and they start to use it as a place for the convicts of Palamilidi to stay, as the center of the Greek defense during the raid of Ibrahim, as the center of the Organization of Tourism and as a place to accomodate the Greek government.  

Nowadays, visitors can reach it with a boat from the port of Nafplion and watch many events that are organized during summer.