Casimir III the Great erected a castle in Ko³o – most likely prior to the founding of the city – as part of an overall enterprise of strengthening the boundaries of the realm. Ko³o castle was mainly intended to protect central Wielkopolska from attacks by the Teutonic Knights. The fortified city played a vital strategic role for some 200 years.
It was established as a 55 m x 40 m rectangle, made of brick with stone foundations, with its longer side arranged on a north-east, south-west axis and enclosed by high crenellated walls.
The castle slowly fell into decay from around the mid-16th century. This was mainly brought about by changes to the defence system after the invention of firearms and artillery.
The entire length of south-west line of walls to a height of 4 m (supported by abutments), fragments of the walls of the short sides of the foundation, and the tower are all that remain of the onetime castle. The north-west section of walls, on the Warta side, have collapsed due to the foundations having been eroded by the flooding of the river.
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.