According to Greek mythology, Troezen came into being as a result of two ancient cities, Hyperea and Antheia, being unified by Pittheus, who named the new city in honor of his deceased brother, Troezen. The ancient city of Troezen was one of the first cult centres in honour of the sea god Poseidon (in Greek mythology Poseidon is a forebearer of the former king Troezen after whom the city was named).
In 580 BC and in the face of the advancing Persian army Athenian general Themistocles proposed to the city assembly that all the women, children and elderly residents of Athens be evacuated to Troezen while able bodied men were sent to fight the Persians or to man the Athenian fleet. Although Athens was subsequently destroyed its citizens were spared.
During the Classical and Hellenistic periods numerous temples and other buildings were constructed in Troezen including a complex of buildings forming a sanctuary to Asclepius although this was somewhat overshadowed by its rival at nearby Epidauros. Other temples were dedicated to Artemis, Hippolytus, Athena and Aphrodite, traces of which can be found in a forest near Troizina.
In 230 BC the volcano at nearby Methana erupted causing severe earthquakes which destroyed many of the temples and buildings at Troezen leading to a decline of the sanctuary to Asclepius. During the Roman era many of these buildings were restored but as Christianity became predominant material from ancient buildings was used in the construction of churches as can be seen in the Diocese church which dates to the 6th century AD.
References:Duino Castle was built by the Wallsee family in 1389 on the cliffs overlooking the Gulf of Trieste. It replaced an older castle from the 11th century. Over time, the Wallsee family disappeared and the castle, after having been used as a prison, became the residence of the Luogar and Hofer.
At the end of the 19th century it became the property of Prince Alexander von Thurn und Taxis from the Czech branch of the House of Thurn and Taxis. It remains with the family to this day with his great-grandson Prince Carlo Alessandro della Torre e Tasso, Duke of Castel Duino the current owner. The castle has been opened to the public as a museum and park.