But in Chaldea there are some enormous masses of ruins, evidently remains of the vast mounds which formed the substructure of their temples. The grandest of all these and the most interesting is the temple of Nabû at Borsippa (now Birs Nimrod), near Babylon, which has been identified as the temple of the Seven Spheres. This was reconstructed by Nebuchadnezzar, as appears by a well-known inscription. Another example is at Mugheir, which was by at the base, and is even now high, and it is clear that both it and the Birs were built with diminishing stages, presenting a series of grand platforms, decreasing in length as they ascended, and leaving a comparatively small one at top for the temple cell. This has been found, it is supposed, at the Birs Nimroud, of vitrified brick made in ancient ovens.