Three large monoliths called Harold's Stones are located in a field on the eastern side of the B4293 to the south of Trellech. The stones are on slightly elevated ground close to running water and springs, which might be relevant to the choice of site. They are believed to date back to the Bronze Age. Such remains are rare in this part of Wales. They derive their name from a legend that they mark the spot at which three chieftains fell in battle with Harold Godwinson, who defeated the Welsh in Gwent in 1063. In another legend the stones were flung from Skirrid by the mythical Jack o' Kent in a competition with the Devil.
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.