Margaret's Castle is a small Tower house probably built in the 15th century. Only two storeys still exist but there is evidence that it was at least three storeys high. It is vaulted above the ground floor with a rectangular tower with projecting turrets in the north west wall. The doorway between the turrets was protected by a murder-hole. A spiral stairway rises within the west turret.
Ardglass had at least six castles and remains of four of them can still be seen: Ardglass Castle, Cowd Castle, Margaret's Castle and Jordan's Castle.
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.