Innisidgen is the site of two Bronze Age entrance graves on the island of St Mary's in the Isles of Scilly. The two burial monuments, (Upper and Lower Innisidgen) lie on a steep slope of Innisidgen Hill overlooking Crow Sound with a view towards the Eastern Isles.
The Isles of Scilly were originally settled during the Neolithic era, circa 2500 BC. Burial monuments on the islands range in date from the later Neolithic period to the Middle Bronze Age (c.2500-1000 BC). Entrance graves are distinguished by their burial chamber, typically constructed with edge-set slabs, coursed rubble walling or both, and roofed by large covering slabs. The chamber is usually accessible through an opening in the mound's stone outer edge. Excavations of entrance graves have generally uncovered cremation urns, pottery fragments and cremated and unburnt human bones.
The two entrance graves at Innisidgen Hill were built during the Bronze Age. At the time of construction, the burial chambers overlooked a coastal inlet, later known as Crow Sound. During the prehistoric era, this site would have encompassed a wide valley of fields enclosed by stone walls. The remains of a prehistoric field system are located on the northern slope of Innisidgen hill next to the entrance graves, discernible as earth and piles of rubble. No artefacts or human remains were found when both graves were first excavated in 1854.
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.