The last known construction at Stonehenge was about 1600 BC (see ‘Y and Z Holes’ below), and the last known usage of it was likely during the Iron Age. Roman coins and medieval artefacts have all been found in or around the monument but it is unknown if the monument was in continuous use throughout prehistory and beyond — or exactly how it would have been used. Notable is the late 7th-6th century BC large arcing Scroll Trench which deepens E-NE towards Heelstone, and the construction of the massive Iron Age hillfort Vespasian’s Camp built alongside the Avenue near the Avon. The burial of a decapitated 7th century Saxon man was excavated from Stonehenge. The site was known by scholars during the Middle Ages and since then it has been studied and adopted by numerous different groups.