Fragments of bricks, engraved with cuneiform characters thousands of years old, lie mixed with the rubble and sandbags left by the US military on the ancient site of Babylon in Iraq. From April 2003 to June 2004, US troops built embankments, dug ditches and spread gravel to hold the fuel reservoirs needed to supply the heliport of Camp Alpha. Huge graveled avenues were gouged out around the ruins of the palaces of Nebuchadnezzar in order to set up prefabricated buildings which became home to up to 2,000 troops. Camp Alpha was closed in December 2004. However, in a report published in 2005, experts from the British Museum confirmed that damage visible on nine of the dragon casts on the temple's Door of Ishtar, and those on the cobbles of the processional way, were due to vibration caused by the passage of heavy machinery.