The Old Venetian Fortress of Corfu covers the promontory which initially contained the old town of Corfu that had emerged during Byzantine times.
Before the Venetian era the promontory, which lies between the Gulf of Kerkyra to the north and Garitsa Bay to the south, was defended by Byzantine fortifications which the Venetians largely replaced with fortifications of their own design. As part of their defensive plans the Venetians separated the promontory from the rest of the city of Corfu by creating the Contrafossa, a moat which is a sea channel connecting the Gulf of Kerkyra to the North with the Bay of Garitsa to the South, converting the citadel into an artificial island.
The fort successfully repulsed all three major Ottoman sieges: the great siege of 1537, the siege of 1571 and the second great siege of Corfu in 1716.
In 1718 lightning struck the powder magazine at Castel da Mare causing an explosion which created a chain reaction during which three secondary ammunition facilities also exploded, this in turn destroying most buildings inside the castle including the palace of the Captain General of the fortress, and many city buildings. Commander of the fortress and hundreds of others died in the explosion.
The fortress houses today the Public library of Corfu which is located in the old British barracks. The fortress grounds are also used for various types of art and culture exhibits. The Hellenic Music Research Lab of the Ionian University is also located at the Old Fortress.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.