Steyregg Castle dates back to the late 11th century (a similar structure, most likely made from wood, was there already before the turn of the last millenium). After the castle had been hit by two fires in the 18th century the original architecture remained largely untouched afterwards.
The castle was carefully renovated and extended in 2004 and its splendid rooms can be rented for private events. Especially beautiful is the castle chapel (late 13th – early 14th century) with its magnificent gothic frescoes from the 14th century (redone in baroque style in 1680). Parts of Steyregg's former city walls are still in good condition.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.