As the boat approaches the island of Tinos, stands out a tall rock in the middle of the island. This is the imposing Exomvourgo or Xombourgo. The point was chosen, by the inhabitants of the island, since prehistoric times, constructing the tallest castle of the Aegean, at 621 meters. The castle protected the inhabitants from raids of the pirates and the Ottomans. During the period, Tinos was under the Venetian rule, the castle had 5 churches, more than 650 houses, bunkers, water tanks etc., able to accommodate 1000 to 2000 people. The Castle of Tinos or Castle of Agia Eleni, was destroyed in the latest raid of the Ottomans, in 1715. After the capitulation of the then Venetian governor of Tinos, the Rector Bernardo Baldi, they allowed the garrison and the inhabitants to leave, but blew up the whole castle. Today the visitor will find at the foot, the Moni Kardias (Monastery of Heart of Jesus), from where starts the trail to the peak of the rock as well as the remains of the castle. The area offers breathtaking views of the island and the Cyclades islands with the visibility many times being impressive.