The Kastro is a Venetian castle just above Bochali hill and almost hidden among the pine trees. The central gate is marked by a sculpture of St Markos' Lion, which is the crest of Venice. This castle with its huge stones, the embrasures, the towers and cannons, was used to protect the old city of Zakynthos.

The ruined castle walls contain the remains of several churches and is also now home to many species of flora and fauna. The 360 degrees view from the castle tower is unbeatable, it shows the town below and on a clear day it is possible to see mainland Greece and the mountains of the Peloponnese.