In this phase, about 2280 to 1930 BC, the blue stones were re-converted. A portion was set up as a circle between the two Sarsen stones and installed the other in an oval shape in the middle of the monument. Some archaeologists assume that some of the blue stones were brought to this time in the second installment of Wales. The Altar Stone may have been moved within the oval. Work on Stonehenge 3 IV were performed in comparison with his immediate predecessors, rather poor. The blue stones were re-established poorly embedded in the ground and partially overturned quickly.