The castle of Virtsu belonged to vassals of the feudal state Bishopric of Ösel-Wiek - Western part of nowadays Estonia as well as part of Saaremaa and part of Hiiumaa. It was built in 1430 by Uexküll noble family and destroyed already in 16th century. Now the ruined walls are few metres high, but it really looks that there is almost nothing. That's because grass and bush is growing on the ruins.
Reference: Virtual Tourist
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.