Carrickkildavnet or Kildavnet Castle is a tower house located in the southeast corner of Achill Island, across from the Corraun Peninsula. This is an important strategic site, protecting the mouth of Achill Sound and the passage that connects Clew Bay with Blacksod Bay.
Carrickkildavnet Castle was built c. 1429 by the Ó Máille (O'Malley), Kings of Umaill. It was later the stronghold of Gráinne Ní Mháille (Grace O'Malley, c. 1530 – c. 1603), the famous 'pirate queen.'
It is a tower house of four storeys' height. It is vaulted above the first floor and a hole at the corner of this vault is the only access to the higher levels, presumably for defensive reasons. Other defensive features include a mural chamber, machicolation, defensive loops, buttress fortifications at the top and a ruined bawn wall.
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.