Hald Castle was built in 1528 by the bishop Jørgen Friis, who was the last Roman Catholic bishop of Viborg. It is said that Friis was one of the first prisons in Hald tower after the Reformation. The castle was left to decay and in the 1700s it was abandoned. Anyway in late 1800s the owned Christopher Krabbe reconstructed the tower which is today the most visible part of the former castle. Today castle ruins are open to the public for free.
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.